WO2023282010A1 - Double-sided pressure-sensitive adhesive sheet - Google Patents

Double-sided pressure-sensitive adhesive sheet Download PDF

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Publication number
WO2023282010A1
WO2023282010A1 PCT/JP2022/024106 JP2022024106W WO2023282010A1 WO 2023282010 A1 WO2023282010 A1 WO 2023282010A1 JP 2022024106 W JP2022024106 W JP 2022024106W WO 2023282010 A1 WO2023282010 A1 WO 2023282010A1
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Prior art keywords
sensitive adhesive
pressure
double
mass
meth
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PCT/JP2022/024106
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French (fr)
Japanese (ja)
Inventor
直宏 加藤
栄一 井本
匡崇 西脇
健一 山元
茂樹 渡辺
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日東電工株式会社
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Priority to JP2023533492A priority Critical patent/JPWO2023282010A1/ja
Priority to CN202280044836.4A priority patent/CN117545818A/en
Publication of WO2023282010A1 publication Critical patent/WO2023282010A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

  • the present invention relates to a double-sided adhesive sheet.
  • a mobile phone which is a typical mobile device, tends to have thinned main components.
  • the display part of a portable device is mainly composed of an LCD module and a backlight unit, and various sheet-like parts are laminated in order to exhibit functions such as light emission, reflection, light blocking, and light guiding. Therefore, a double-sided adhesive sheet (double-sided adhesive tape) is used for assembling (bonding) these parts.
  • portable electronic devices are often exposed to the risk of falling due to their usage patterns.
  • double-sided pressure-sensitive adhesive sheets used in portable electronic devices are required to have impact resistance so that they are less likely to be damaged or peeled off from parts due to the impact of dropping the portable electronic device.
  • Patent Documents 1 to 3 disclose, for example, known double-sided pressure-sensitive adhesive sheets that are used in mobile electronic devices and have excellent impact resistance.
  • the double-sided adhesive sheets used for portable electronic devices have high shear adhesive strength to prevent peeling due to deformation of the adherend. required to have
  • a double-sided PSA sheet with a flexible PSA layer tends to have excellent impact resistance, but tends to have low shear adhesive strength.
  • the adhesive layer of the double-sided adhesive sheet is hard, the shear adhesive strength increases, but the adhesiveness of the surface tends to be low. ) tends to be inferior to For this reason, it has been considered difficult to realize a double-faced PSA sheet that has excellent impact resistance, high shear adhesive strength, and excellent initial tackiness.
  • Patent Documents 1 to 3 do not mention excellent impact resistance, high shear adhesive strength, and excellent initial tackiness.
  • the present invention was conceived under such circumstances, and its object is to provide a double-sided pressure-sensitive adhesive sheet having excellent impact resistance, high shear adhesive strength, and excellent initial adhesiveness. to do.
  • a double-sided pressure-sensitive adhesive sheet having no substrate, a base polymer composition in the pressure-sensitive adhesive layer constituting the double-sided pressure-sensitive adhesive sheet By specifying the storage elastic modulus G′ and glass transition temperature under two temperature conditions, and the 180° peel strength of the double-sided PSA sheet against a stainless steel plate, it has excellent impact resistance, high shear adhesive strength, and It was found to be excellent in initial adhesiveness.
  • the present invention has been completed based on these findings.
  • the present invention is a double-sided pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer
  • the pressure-sensitive adhesive layer is an active energy ray-curable acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer,
  • the acrylic polymer contains 50% by mass or more of structural units derived from a (meth)acrylic acid alkyl ester (A) having a linear or branched alkyl group having 2 to 7 carbon atoms,
  • the pressure-sensitive adhesive layer has a glass transition temperature of 0° C.
  • a storage elastic modulus G′ of 10 MPa or higher at ⁇ 20° C. and a storage elastic modulus G′ of 0.05 MPa or higher at 65° C.
  • a double-sided pressure-sensitive adhesive sheet having a 180° peel strength against a stainless steel plate measured at 23°C of 20 N/20 mm or more when a polyethylene terephthalate film having a thickness of 50 ⁇ m is attached to one adhesive surface of the double-sided pressure-sensitive adhesive sheet. do.
  • the (meth)acrylic acid alkyl ester (A) contains butyl (meth)acrylate, and the proportion of structural units derived from butyl (meth)acrylate in the acrylic polymer is preferably 50% by mass or more. .
  • the above acrylic polymer preferably contains a polyfunctional monomer as a monomer component that constitutes the polymer.
  • the acrylic polymer preferably has a structural portion derived from a photopolymerization initiator.
  • the above acrylic polymer preferably contains structural units derived from a monomer component (B) having a homopolymer glass transition temperature of 0°C or higher and having a non-aromatic ring.
  • the double-sided pressure-sensitive adhesive sheet is preferably for fixing members to each other in electrical and electronic equipment.
  • the present invention also provides an electrical and electronic device comprising the double-sided pressure-sensitive adhesive sheet, wherein both pressure-sensitive adhesive surfaces of the double-sided pressure-sensitive adhesive sheet fix members to each other.
  • the double-sided pressure-sensitive adhesive sheet of the present invention has excellent impact resistance, high shear adhesive strength, and excellent initial adhesiveness. Therefore, when used in, for example, a portable electronic device, the members can be sufficiently fixed to each other, and even when the adherend is subjected to a drop impact or the adherend is deformed, it is difficult to peel off.
  • the double-sided pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer, and is a so-called "substrate-less" double-sided pressure-sensitive adhesive sheet that does not have a substrate.
  • the pressure-sensitive adhesive layer is an active energy ray-curable acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer, has a glass transition temperature of 0° C. or higher, and a storage elastic modulus G′ at ⁇ 20° C. of 10 MPa or higher. , and a storage modulus G′ at 65° C. of 0.05 MPa or more.
  • the acrylic polymer contained in the acrylic pressure-sensitive adhesive layer contains 50% by mass or more of structural units derived from a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 2 to 7 carbon atoms.
  • the pressure-sensitive adhesive layer may be referred to as "the pressure-sensitive adhesive layer of the present invention".
  • the pressure-sensitive adhesive layer constituting the double-sided pressure-sensitive adhesive sheet of the present invention may be a single layer or multiple layers.
  • the double-sided pressure-sensitive adhesive sheet of the present invention is composed of a plurality of pressure-sensitive adhesive layers, each of the plurality of pressure-sensitive adhesive layers is the pressure-sensitive adhesive layer of the present invention.
  • the plurality of pressure-sensitive adhesive layers may be the same pressure-sensitive adhesive layer, or may be pressure-sensitive adhesive layers having different compositions, thicknesses, physical properties, and the like.
  • FIG. 1 is a schematic cross-sectional view showing one embodiment of the double-sided pressure-sensitive adhesive sheet of the present invention.
  • a double-sided pressure-sensitive adhesive sheet 1 is composed of a single pressure-sensitive adhesive layer 2 of the present invention. Release liners 3 and 4 are attached to the adhesive surfaces of the adhesive layer 2, respectively.
  • the pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer exhibiting adhesiveness.
  • the base polymer refers to a main component among the polymer components in the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, for example, a polymer component contained in an amount exceeding 50% by mass.
  • the proportion of the base polymer in the pressure-sensitive adhesive layer is preferably 60% by mass or more, more preferably 70% by mass or more, relative to 100% by mass of the total amount of the pressure-sensitive adhesive layer.
  • the above acrylic polymer is a polymer containing an acrylic monomer (a monomer having a (meth)acryloyl group in the molecule) as a monomer component that constitutes the polymer. That is, the acrylic polymer contains structural units derived from acrylic monomers. In addition, acrylic polymer may use only 1 type, and may use 2 or more types. Moreover, the said acrylic polymer may contain only 1 type of acrylic monomers as a monomer component, and may contain 2 or more types. In the present specification, "(meth)acrylic” means “acrylic” and/or “methacrylic” (one or both of "acrylic” and “methacrylic”), and the same applies to others. .
  • the acrylic polymer is a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 2 to 7 carbon atoms (sometimes referred to as "(meth)acrylic acid alkyl ester (A)"). It is a polymer composed (formed) as an essential monomer component. That is, the acrylic polymer contains a (meth)acrylic acid alkyl ester (A) as a structural unit.
  • the acrylic polymer may contain only one type of (meth)acrylic acid alkyl ester (A) as a monomer component, or may contain two or more types.
  • the (meth)acrylic acid alkyl ester (A) is not particularly limited, but examples thereof include ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, Isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic and heptyl acid.
  • butyl (meth)acrylate is preferable from the viewpoint of selecting a lower storage elastic modulus G'.
  • the proportion of the (meth)acrylic acid alkyl ester (A) in 100% by mass of the total amount of all monomer components constituting the acrylic polymer is 50% by mass or more, preferably 60% by mass or more, more preferably 65% by mass. % by mass or more.
  • the proportion is preferably 94% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.
  • the ratio of butyl (meth)acrylate is within the above range.
  • the acrylic polymer together with the (meth)acrylic acid alkyl ester (A), is a monomer component having a homopolymer glass transition temperature of 0 ° C. or higher and having a non-aromatic ring (referred to as "monomer component (B)" It is preferably a polymer constituted (formed) as a monomer component.
  • the acrylic polymer may contain only one monomer component (B) as a monomer component, or may contain two or more monomer components.
  • the non-aromatic ring includes a non-aromatic hydrocarbon ring and a non-aromatic heterocyclic ring.
  • the non-aromatic ring may be either saturated or unsaturated.
  • Examples of the non-aromatic hydrocarbon ring include aliphatic hydrocarbon rings such as cycloalkane rings such as cyclopentane ring, cyclohexane ring, cycloheptane ring and cyclooctane ring; cycloalkene rings such as cyclohexene ring; bridging hydrocarbon rings such as bicyclic hydrocarbon rings and tricyclic or higher aliphatic hydrocarbon rings; Bicyclic hydrocarbon rings include pinane ring, pinene ring, bornane ring, norbornane ring, norbornene ring and the like.
  • Tricyclic or higher aliphatic hydrocarbon rings include, for example, dicyclopentane ring, dicyclopentene ring, adamantane ring, tricyclopentane ring, tricyclopentene ring and the like. .
  • non-aromatic heterocyclic ring examples include an oxygen atom-containing heterocyclic ring, a nitrogen atom-containing heterocyclic ring, a sulfur atom-containing heterocyclic ring, and the like.
  • the oxygen atom-containing heterocyclic ring includes oxolane ring, oxane ring, oxole ring, pyran ring, caprolactone ring, caprolactam ring, heterocyclic ring containing oxygen atom and nitrogen atom, and the like.
  • the nitrogen atom-containing heterocyclic ring includes azolidine ring, azinane ring, azole ring, piperidine ring, caprolactam ring, heterocyclic ring containing oxygen atom and nitrogen atom, heterocyclic ring containing nitrogen atom and sulfur atom, and the like.
  • the sulfur atom-containing heterocyclic ring includes thiolane ring, thiol ring, heterocyclic ring containing nitrogen atom and sulfur atom, and the like.
  • a heterocyclic ring containing an oxygen atom and a nitrogen atom includes a morpholine ring and the like.
  • a heterocyclic ring containing a nitrogen atom and a sulfur atom includes a thiazine ring, a thiazole ring, and the like.
  • the number of atoms constituting the non-aromatic ring is preferably 5-12, more preferably 6-10.
  • the monomer component (B) is preferably a monomer component having a carbon-carbon double bond (e.g., (meth)acryloyl group, vinyl group, etc.) having active energy ray polymerizability and a non-aromatic ring. Examples thereof include (meth)acrylic acid esters having a non-aromatic ring in the ester portion, and monomer components having a vinyl group and a non-aromatic heterocyclic ring.
  • the non-aromatic ring is directly bonded to the (meth)acryloyl group, or bonded to the (meth)acryloyl group via an oxygen atom or an oxyalkylene group. is preferred.
  • the non-aromatic ring among others, an aliphatic hydrocarbon ring and a nitrogen atom-containing heterocyclic ring are preferable.
  • the monomer component (B) in which the non-aromatic ring is an aliphatic hydrocarbon ring include, for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, (Meth)acrylic acid cycloalkyl ester such as cyclooctyl (meth)acrylate; (meth)acrylic acid ester having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; dicyclopentanyl (meth) ) acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2 -Methyl-2-adamantyl (meth)acrylate,
  • the monomer component (B) in which the non-aromatic ring is a nitrogen atom-containing heterocyclic ring include N-(meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, N-vinyl-2- piperidone, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, N-vinylpiperazine, N- Vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyrimidine, 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, vinylpyridazine, (meth ) acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine and
  • the Tg of the homopolymer of the monomer component (B) is 0°C or higher, preferably 10°C or higher, more preferably 60°C or higher.
  • the Tg is preferably 50° C. or lower, more preferably 20° C. or lower, from the viewpoint of superior initial adhesiveness.
  • the "glass transition temperature (Tg) when forming a homopolymer” means "the glass transition temperature of the homopolymer of the monomer ( Tg)", specifically, numerical values are listed in "Polymer Handbook” (3rd edition, John Wiley & Sons, Inc., 1987).
  • the Tg of a homopolymer of a monomer not described in the above literature refers to, for example, a value obtained by the following measuring method (see JP-A-2007-51271).
  • a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser was charged with 100 parts by mass of a monomer, 0.2 parts by mass of 2,2'-azobisisobutyronitrile and ethyl acetate as a polymerization solvent. 200 parts by mass are added and stirred for 1 hour while nitrogen gas is introduced. After oxygen is removed from the polymerization system in this manner, the temperature is raised to 63° C. and the reaction is allowed to proceed for 10 hours. Then, it is cooled to room temperature to obtain a homopolymer solution having a solid concentration of 33% by mass.
  • the homopolymer solution is then cast onto a release liner and dried to form a test sample (sheet homopolymer) having a thickness of about 2 mm. Then, this test sample was punched out into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear strain at a frequency of 1 Hz using a viscoelasticity tester (trade name “ARES”, manufactured by Rheometrics Co., Ltd.). The viscoelasticity is measured in the shear mode at a heating rate of 5°C/min in the region of -70 to 150°C, and the peak top temperature of tan ⁇ is defined as the Tg of the homopolymer.
  • ARES viscoelasticity tester
  • the ratio of the monomer component (B) in the total amount of 100% by mass of all the monomer components constituting the acrylic polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more. be.
  • the storage elastic modulus G′ (particularly, the storage elastic modulus G′ at ⁇ 20° C.) is high, and the ratio of the monomer component (B), which is excellent in impact resistance, is 60% by mass.
  • the following is preferable, more preferably 50% by mass or less, and still more preferably 40% by mass or less.
  • the above ratio is 60% by mass or less, the flexibility is improved, and the adhesiveness to the adherend and the shear adhesive strength can be improved.
  • the acrylic polymer may contain a copolymerizable monomer together with the (meth)acrylic acid alkyl ester (A) and the monomer component (B) as a monomer component constituting the polymer. That is, the acrylic polymer may contain a copolymerizable monomer as a structural unit.
  • the above copolymerizable monomers may be used alone or in combination of two or more.
  • a carboxy group-containing monomer and/or an acid anhydride can be used to form a pressure-sensitive adhesive layer having good adhesiveness even if it is thin, and from the viewpoint of improving cohesion and improving impact resistance.
  • Monomers are preferred.
  • the carboxy group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.
  • the acid anhydride monomer include maleic anhydride and itaconic anhydride.
  • the ratio of the carboxy group-containing monomer and/or the acid anhydride monomer in the total amount of 100% by mass of all the monomer components constituting the acrylic polymer is not particularly limited, but is preferably 0.2% by mass or more, More preferably 1% by mass or more, still more preferably 5% by mass or more.
  • the proportion is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.
  • the copolymerizable monomer may further contain a functional group-containing monomer for the purpose of introducing a cross-linking point into the acrylic polymer or increasing the cohesion of the acrylic polymer.
  • a functional group-containing monomer examples include hydroxyl group-containing monomers, nitrogen atom-containing monomers (excluding those corresponding to the monomer component (B)), keto group-containing monomers, alkoxysilyl group-containing monomers, sulfonic acid group-containing monomers, Examples include phosphoric acid group-containing monomers. Only one kind of the functional group-containing monomer may be used, or two or more kinds thereof may be used.
  • hydroxy group-containing monomer examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) ) hydroxyalkyl (meth)acrylates such as acrylates; unsaturated alcohols such as vinyl alcohol and allyl alcohol; polypropylene glycol mono(meth)acrylates;
  • Examples of the nitrogen atom-containing monomers include amide group-containing monomers, amino group-containing monomers, and cyano group-containing monomers.
  • Examples of the amide group-containing monomer include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N -Methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide and the like.
  • amino group-containing monomer examples include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate and the like.
  • cyano group-containing monomer examples include acrylonitrile and methacrylonitrile.
  • keto group-containing monomer examples include diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, and vinyl acetoacetate.
  • alkoxysilyl group-containing monomer examples include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-( meth)acryloxypropylmethyldiethoxysilane and the like.
  • sulfonic acid group-containing monomer examples include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth) ) acryloyloxynaphthalenesulfonic acid and the like.
  • Examples of the phosphoric acid group-containing monomer include 2-hydroxyethyl acryloyl phosphate.
  • the ratio of the functional group-containing monomer in the total amount of 100% by mass of all the monomer components constituting the acrylic polymer is, for example, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 5% by mass. % or more, or 10% by mass or more.
  • the above ratio may be, for example, 40% by mass or less, 20% by mass or less, or may be substantially absent.
  • substantially not included refers to unintentional inclusion, such as unavoidable mixing, rather than active blending. It is 0.01% by mass or less.
  • the copolymerizable monomer may further contain other monomers.
  • the other monomers include vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate; aromatic vinyl compounds such as styrene, substituted styrene ( ⁇ -methylstyrene, etc.), and vinyl toluene; ethylene, propylene.
  • the proportion of the other monomers in the total amount of 100% by mass of all monomer components constituting the acrylic polymer may be, for example, 0.05% by mass or more, or 0.5% by mass or more.
  • the above ratio may be, for example, 20% by mass or less, 10% by mass or less, 5% by mass or less, or may be substantially absent.
  • the acrylic polymer may contain, as a monomer component constituting the polymer, a polyfunctional monomer copolymerizable with the monomer component forming the acrylic polymer, in order to form a crosslinked structure in the polymer skeleton.
  • the polyfunctional monomer include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, penta Polyfunctional (meth)acrylates such as erythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate; epoxy (meth)acrylates (e.g., poly glycidyl (meth)acrylate), polyester (meth)acrylate, urethane
  • the proportion of the polyfunctional monomer in 100% by mass of the total amount of all monomer components constituting the acrylic polymer is preferably 0.05% by mass or more, more preferably 0.07% by mass, and still more preferably 0.07% by mass. It is 10% by mass or more.
  • the above ratio may be 5% by mass or less, 3% by mass or less, or may be substantially absent.
  • the acrylic polymer preferably has a structural portion derived from a photopolymerization initiator. That the acrylic polymer has a structural part derived from a photopolymerization initiator means that the acrylic polymer and the pressure-sensitive adhesive layer of the present invention are a polymer or a cured pressure-sensitive adhesive layer polymerized by irradiation with active energy rays. do. Examples of the photopolymerization initiator include those described below.
  • the acrylic polymer is preferably a polymerization reaction product obtained by polymerizing a composition containing one or more selected from the group consisting of acrylic partial polymers, acrylic oligomers, and monomer components.
  • the monomer component contains at least an acrylic monomer.
  • the above-mentioned "partioned "partially polymerized product” may also be referred to as "prepolymer", “syrup”, and the like.
  • Each of the acrylic partial polymer, the acrylic oligomer, and the monomer component may be used alone or in combination of two or more.
  • the monomer component that can be contained in the composition may be referred to as "monomer component (C)".
  • the acrylic polymer is preferably a polymerization reaction product of a composition containing an acrylic partial polymer, and is preferably a polymerization reaction product of a composition containing an acrylic partial polymer and the monomer component (C).
  • the acrylic polymer is a polymerization reaction product of a composition containing a monomer component (C) together with an acrylic partial polymer, the monomer component (C) forms a low-molecular-weight polymer in the pressure-sensitive adhesive layer of the present invention.
  • a double-sided pressure-sensitive adhesive sheet having particularly excellent initial pressure-sensitive adhesiveness can be easily produced.
  • Both the acrylic partial polymer and the acrylic oligomer are compounds composed of an acrylic monomer as an essential monomer component.
  • Examples of the monomer component and the monomer component (C) constituting the acrylic partial polymer and the acrylic oligomer include those exemplified and explained as the monomer component constituting the acrylic polymer.
  • the acrylic partial polymer is obtained by polymerizing the monomer components at a polymerization conversion rate of 95% by mass or less, for example.
  • the polymerization conversion rate is preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less.
  • the polymerization conversion rate is preferably 1% by mass or more, more preferably 5% by mass or more.
  • the above acrylic partial polymer contains an acrylic monomer as a structural unit.
  • the acrylic partial polymer preferably contains (A) a (meth)acrylic acid alkyl ester as a structural unit.
  • the (meth)acrylic acid alkyl ester (A) contained as the structural unit may be of one type or two or more types.
  • the proportion of the (meth)acrylic acid alkyl ester (A) in 100% by mass of the total amount of all monomer components constituting the acrylic partial polymer is preferably 50% by mass or more, more preferably 60% by mass. above, more preferably at least 65% by mass.
  • the proportion is preferably 94% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.
  • the acrylic partial polymer preferably contains the monomer component (B) as a structural unit.
  • the monomer component (B) contained as the structural unit may be of one type or two or more types.
  • the proportion of the monomer component (B) in the total amount of 100% by mass of all the monomer components constituting the acrylic partial polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably It is 15% by mass or more.
  • the storage elastic modulus G' in particular, the storage elastic modulus G' at -20°C
  • the proportion of the monomer component (B) is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. When the above ratio is 60% by mass or less, the flexibility is improved, and the adhesiveness to the adherend and the shear adhesive strength can be further improved.
  • the acrylic partial polymer may contain the copolymerizable monomer as a structural unit.
  • the copolymerizable monomer among others, from the viewpoint of improving cohesive strength and excellent impact resistance, and from the viewpoint of being able to form a pressure-sensitive adhesive layer having good adhesion even if it is thin, a carboxy group-containing monomer and / or Anhydride monomers are preferred.
  • the ratio of the carboxy group-containing monomer and/or the acid anhydride monomer in the total amount of 100% by mass of all the monomer components constituting the acrylic partial polymer is not particularly limited, but is preferably 0.2% by mass or more. It is preferably 1% by mass or more, and still more preferably 5% by mass or more. The proportion is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 11% by mass or less.
  • the above acrylic polymer may be a polymerization reaction product of a composition containing an acrylic partial polymer and an acrylic oligomer.
  • the storage elastic modulus G' at -20°C is further improved.
  • the acrylic oligomer preferably has a weight average molecular weight of 2,500 to 10,000, more preferably 3,000 to 8,000.
  • the said weight average molecular weight can be calculated
  • the above acrylic oligomer contains an acrylic monomer as a structural unit.
  • the acrylic oligomer preferably contains a monomer component (B) as a structural unit.
  • the monomer component contained as the structural unit may be of one type or two or more types.
  • the proportion of the monomer component (B) in the total amount of 100% by mass of all the monomer components constituting the acrylic oligomer is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 55% by mass. % or more.
  • the ratio is preferably 90% by mass or less, more preferably 80% by mass or less.
  • the above acrylic oligomer preferably contains methyl methacrylate (MMA) as a structural unit.
  • MMA methyl methacrylate
  • the proportion of methyl methacrylate in all monomer components constituting the acrylic oligomer is preferably 10% by mass or more, more preferably 20% by mass or more.
  • the proportion is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less.
  • the acrylic oligomer may contain the copolymerizable monomer as a structural unit.
  • the content of the acrylic oligomer is preferably 0.5 to 35 parts by mass, more preferably 2 to 20 parts by mass, and still more preferably 4 parts by mass with respect to 100 parts by mass of the acrylic partial polymer. ⁇ 10 parts by mass.
  • the storage elastic modulus G' at -20°C tends to increase.
  • the monomer component (C) examples include those exemplified and explained as the monomer components that the acrylic polymer can contain as structural units.
  • the monomer component (C) preferably contains a monomer copolymerizable with the monomer component (B) and/or the monomer component forming the acrylic partial polymer.
  • Examples of the copolymerizable monomer include the copolymerizable monomers described above.
  • the proportion of the monomer component (B) in the monomer component (C) is preferably 60% by mass or more, more preferably 70% by mass or more.
  • the monomer that can be copolymerized with the monomer component that forms the acrylic partial polymer among others, from the viewpoint of being able to form a pressure-sensitive adhesive layer that is thin but has good adhesion, a carboxy group-containing monomer and/or an acid Anhydride monomers are preferred.
  • the monomer component (C) contains the copolymerizable monomer
  • the ratio of the copolymerizable monomer in the monomer component (C) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass. % or more.
  • the proportion of the monomer component (B) in the monomer component (C) is preferably 60 to 95% by mass, more preferably 70%. ⁇ 90% by mass.
  • the proportion of the copolymerizable monomer in the monomer component (C) is not particularly limited, but is preferably 5 to 40% by mass, more preferably 10 to 30% by mass.
  • the content of the monomer component (C) is preferably 1 to 30 parts by mass, more preferably 10 to 20 parts by mass, based on 100 parts by mass of the acrylic partial polymer.
  • the initial adhesive strength is even more excellent.
  • the storage elastic modulus G' is further improved, and the shear adhesive strength is further increased.
  • the acrylic partial polymer and the acrylic oligomer are obtained by polymerizing monomer components.
  • the acrylic polymer is obtained by polymerizing a composition containing one or more selected from the group consisting of the acrylic partial polymer, the acrylic oligomer, and the monomer component (C).
  • These polymerization methods are not particularly limited, but include, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a thermal polymerization method, and a polymerization method by active energy ray irradiation (active energy ray polymerization method).
  • the bulk polymerization method, the thermal polymerization method, and the active energy ray polymerization method are preferable from the viewpoints of the transparency of the pressure-sensitive adhesive layer and the cost.
  • various general solvents may be used in the polymerization of the above-mentioned monomer components.
  • the solvent include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane, methylcyclohexane and the like. alicyclic hydrocarbons; and organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone.
  • a solvent may use only 1 type, and may use 2 or more types.
  • a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) may be used depending on the type of polymerization reaction.
  • a polymerization initiator may use only 1 type, and may use 2 or more types.
  • the thermal polymerization initiator is not particularly limited. , benzoyl peroxide, hydrogen peroxide, etc.), substituted ethane-based initiators such as phenyl-substituted ethane, aromatic carbonyl compounds, redox-based polymerization initiators, and the like.
  • the azo polymerization initiator disclosed in JP-A-2002-69411 is preferable.
  • the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis(2-methylpropionate)dimethyl, 4,4'-azobis-4-cyanovaleric acid and the like.
  • the amount of the thermal polymerization initiator to be used may be a normal amount, for example, 0.005 to 1 part by mass, preferably 0.01 to 1 part by mass based on 100 parts by mass of the monomer component. can do.
  • the photopolymerization initiator is not particularly limited. Examples include active oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators. Other examples include acylphosphine oxide photopolymerization initiators and titanocene photopolymerization initiators.
  • benzoin ether-based photopolymerization initiator examples include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one, anisole methyl ether and the like.
  • acetophenone-based photopolymerization initiator examples include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, 4-phenoxydichloroacetophenone, 4-(t-butyl ) and dichloroacetophenone.
  • Examples of the ⁇ -ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. be done.
  • Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride.
  • Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)-oxime.
  • Examples of the benzoin-based photopolymerization initiator include benzoin.
  • Examples of the benzyl-based photopolymerization initiator include benzyl.
  • benzophenone-based photopolymerization initiator examples include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, ⁇ -hydroxycyclohexylphenyl ketone, and the like.
  • ketal-based photopolymerization initiator examples include benzyl dimethyl ketal.
  • Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.
  • Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.
  • titanocene-based photopolymerization initiator examples include bis( ⁇ 5 -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl ) and titanium.
  • the amount of the photopolymerization initiator used may be a normal amount, for example, 0.01 to 3 parts by mass, preferably 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the monomer component. You can choose from
  • the adhesive layer of the present invention preferably further contains a filler.
  • a filler By blending the filler, it becomes easy to adjust the storage elastic modulus G' at -20°C and 65°C. Only one type of the filler may be used, or two or more types may be used.
  • the shape of the filler is not particularly limited, and a particulate or fibrous filler can be used. Among them, a particulate form is preferable.
  • the filler may be either an organic substance or an inorganic substance.
  • Examples of materials constituting the above inorganic substances include metals such as copper, silver, gold, platinum, nickel, aluminum, chromium, iron, and stainless steel; aluminum oxide, silicon oxide (silicon dioxide), titanium oxide, zirconium oxide, and zinc oxide. , tin oxide, copper oxide, nickel oxide and other metal oxides; aluminum hydroxide, boehmite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, silicic acid, iron hydroxide, copper hydroxide, barium hydroxide, zirconium oxide water hydrates, tin oxide hydrates, basic magnesium carbonate, hydrotalcite, dawsonite, borax, zinc borate and other metal hydroxides and hydrated metal compounds; silicon carbide, boron carbide, nitrogen carbide, calcium carbide, etc.
  • metals such as copper, silver, gold, platinum, nickel, aluminum, chromium, iron, and stainless steel
  • aluminum oxide silicon oxide (silicon dioxide), titanium oxide, zirconium oxide, and zinc oxide.
  • nitrides such as aluminum nitride, silicon nitride, boron nitride, gallium nitride
  • carbonates such as calcium carbonate
  • titanates such as barium titanate and potassium titanate
  • carbon black, carbon tube (carbon nanotube), carbon fiber carbonaceous materials such as diamond
  • inorganic materials such as glass
  • natural raw material particles such as volcanic shirasu, clay, sand, and the like.
  • materials constituting the above organic matter include polystyrene, acrylic resin (e.g., polymethyl methacrylate), phenol resin, benzoguanamine resin, urea resin, silicone resin, polyester, polyurethane, polyethylene, polypropylene, polyamide (e.g., nylon), and polyimide. , and polymers such as polyvinylidene chloride.
  • the filler may have a hollow body structure.
  • the hollow portion (internal space of the hollow particles) of the filler having the hollow body structure may be in a vacuum state or may be filled with a medium.
  • the medium include inert gases such as nitrogen and argon, air, and volatile solvents.
  • a filler whose surface is composed of an organic or inorganic substance other than an acrylic resin and a filler having a hollow body structure are preferable. These fillers have little interaction with the acrylic component in the acrylic pressure-sensitive adhesive layer or have a hollow body structure, so when the pressure-sensitive adhesive layer is stretched, it is difficult to break, and the double-sided pressure-sensitive adhesive sheet can be attached to the adherend. Excellent peelability (reworkability) when peeling off after bonding.
  • the average particle size of the particulate filler is, for example, 0.5 to 80 ⁇ m, preferably 1 to 40 ⁇ m.
  • the pressure-sensitive adhesive layer can have an appropriate hardness.
  • the said average particle diameter is a median diameter (D50) measured by a dynamic light-scattering method.
  • the proportion of the filler in the adhesive layer of the present invention is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, relative to 100% by mass of the total amount of the adhesive layer.
  • the hardness of the pressure-sensitive adhesive layer can be made appropriate. Moreover, it is excellent in reworkability.
  • the adhesive layer of the present invention may contain a coloring agent.
  • the pressure-sensitive adhesive layer is colored by containing a coloring agent, and the double-sided pressure-sensitive adhesive sheet of the present invention is excellent in visibility and design.
  • the coloring agent may be a pigment or a dye. Examples of coloring agents include black coloring agents, cyan coloring agents, magenta coloring agents, and yellow coloring agents. A black colorant is preferable from the viewpoint of better visibility and design.
  • the coloring agent may contain only one kind, or may contain two or more kinds.
  • the proportion of the coloring agent in the pressure-sensitive adhesive layer of the present invention is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, with respect to 100% by mass of the total amount of the pressure-sensitive adhesive layer. .
  • black colorants include carbon black, carbon nanotubes, graphite (graphite), copper oxide, manganese dioxide, azo pigments such as azomethine azo black, aniline black, perylene black, titanium black, cyanine black, activated carbon, and ferrite. , magnetite, chromium oxide, iron oxide, molybdenum disulfide, complex oxide-based black dyes, anthraquinone-based organic black dyes, and azo-based organic black dyes.
  • carbon black include furnace black, channel black, acetylene black, thermal black and lamp black.
  • a black colorant C.I. I. Solvent Black 3, 7, 22, 27, 29, 34, 43, 70; C.I. I.
  • cyan colorant for example, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95; C.I. I. Acid Blue 6, 45; C.I. I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17, 17:1, 18, 22, 25, 56, 60, 63, 65, 66; C.I. I. Bat Blue 4; 60, C.I. I. Pigment Green 7 and the like.
  • magenta colorant for example, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122; C.I. I. disperse thread 9;C. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Disperse Violet 1; C.I. I. Basic red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28 and the like.
  • magenta colorants include C.I. I.
  • yellow colorants examples include C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162; I. Pigment Orange 31, 43; C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 113, 114, 116, 117, 120, 128, 129, 133, 138, 139 , 147, 150, 151, 153, 154, 155, 156, 167, 172, 173, 180, 185, 195; I. Bat Yellow 1, 3, 20 and the like.
  • the pressure-sensitive adhesive layer of the present invention may optionally further contain a cross-linking agent, a cross-linking accelerator, an anti-aging agent, an antioxidant, a plasticizer, a softening agent, a surfactant, an antistatic agent, a surface lubricant, and a leveling agent.
  • a light stabilizer, an ultraviolet absorber, a polymerization inhibitor, a foil-like material, and an antirust agent may be contained within a range that does not impair the effects of the present invention. Only one kind of the above additives may be used, or two or more kinds thereof may be used.
  • the pressure-sensitive adhesive layer of the present invention has a storage modulus G′ at ⁇ 20° C. of 10 MPa or more, preferably 50 MPa or more, more preferably 100 MPa or more, still more preferably 200 MPa or more, and particularly preferably 300 MPa or more.
  • the storage elastic modulus G' at -20°C is the property of the pressure-sensitive adhesive layer at low temperatures, and can be replaced with the property when impacted at a relatively high speed.
  • the storage elastic modulus G' at such a low temperature of -20°C is 10 MPa or more, for example, the member to which the double-sided pressure-sensitive adhesive sheet is applied is excellent in impact resistance when dropped at high speed.
  • the storage modulus G' can be calculated using a dynamic viscoelasticity measurement (DMA) device.
  • DMA dynamic viscoelasticity measurement
  • the pressure-sensitive adhesive layer of the present invention has a storage modulus G′ at 65° C. of 0.05 MPa or more, preferably 0.06 MPa or more, more preferably 0.08 MPa or more, and still more preferably 0.10 MPa. That's it.
  • the storage elastic modulus G' at 65°C is the property of the pressure-sensitive adhesive layer at relatively high temperatures, and can be replaced with the property when subjected to low speed impact. Since the storage elastic modulus G' at 65°C is 0.05 MPa or more, the pressure-sensitive adhesive layer of the present invention has high shear adhesive strength.
  • the storage modulus G' can be calculated using a dynamic viscoelasticity measurement (DMA) device.
  • DMA dynamic viscoelasticity measurement
  • the adhesive layer of the present invention preferably has a storage modulus G' at 23°C of 0.10 MPa or more, more preferably 0.21 MPa or more, and still more preferably 0.25 MPa or more.
  • a storage modulus G' at 23°C 0.10 MPa or more, more preferably 0.21 MPa or more, and still more preferably 0.25 MPa or more.
  • the storage modulus G' can be calculated using a dynamic viscoelasticity measurement (DMA) device.
  • DMA dynamic viscoelasticity measurement
  • the glass transition temperature (Tg) of the adhesive layer of the present invention is 0°C or higher, preferably 2°C or higher, and more preferably 5°C or higher.
  • Tg is 0° C. or higher, the storage elastic modulus G′ is high and the impact resistance is excellent.
  • the above Tg is, for example, 50° C. or lower.
  • the Tg can be calculated using a dynamic viscoelasticity measurement (DMA) device.
  • DMA dynamic viscoelasticity measurement
  • the peak top value of tan ⁇ of the pressure-sensitive adhesive layer of the present invention is preferably 0.5 or more, more preferably 1.0 or more, and still more preferably 1.5 or more.
  • the peak top value of tan ⁇ is 0.5 or more, the impact resistance is more excellent.
  • the above tan ⁇ can be calculated using a dynamic viscoelasticity measurement (DMA) device.
  • the adhesive layer of the present invention is an active energy ray-curable adhesive layer. That is, the pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive layer formed from an active energy ray-curable pressure-sensitive adhesive composition. As a result, the double-sided pressure-sensitive adhesive sheet of the present invention has dense cross-linking and can produce a high-strength pressure-sensitive adhesive, which has excellent impact resistance and high shear adhesive strength.
  • the active energy rays include ionizing radiation such as ⁇ -rays, ⁇ -rays, ⁇ -rays, neutron beams and electron beams, and ultraviolet rays, with ultraviolet rays being particularly preferred. That is, the active energy ray-curable pressure-sensitive adhesive layer is preferably an ultraviolet-curable pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive layer of the present invention can be produced, for example, by applying (coating) the above-described pressure-sensitive adhesive composition onto a release liner and, if necessary, drying and solidifying the solvent by heating to volatilize the pressure-sensitive adhesive composition. It can be produced by irradiating the layer with an active energy ray to cure it. Moreover, you may heat-dry further as needed.
  • the adhesive composition (acrylic adhesive composition) forming the adhesive layer of the present invention for example, the acrylic partial polymer, the acrylic oligomer, or a monomer mixture containing the monomer component (C) is essential.
  • the acrylic adhesive composition used as a component etc. are mentioned.
  • the pressure-sensitive adhesive composition includes a partial polymer of a monomer mixture containing (meth)acrylic acid alkyl ester (A) and monomer component (B), monomer component (C), and polyfunctional It preferably contains at least a polar monomer and a photopolymerization initiator. In addition, it may contain acrylic oligomers, fillers, colorants, and the like.
  • the double-sided pressure-sensitive adhesive sheet of the invention is composed of the pressure-sensitive adhesive layer of the invention.
  • the thickness of the double-sided pressure-sensitive adhesive sheet is preferably 50-500 ⁇ m, more preferably 100-300 ⁇ m. When the thickness is 50 ⁇ m or more, the adhesiveness and conformability to the adherend are excellent. When the thickness is 500 ⁇ m or less, the thickness of the double-sided pressure-sensitive adhesive sheet can be made thinner.
  • the thickness of the double-sided pressure-sensitive adhesive sheet refers to the thickness from one pressure-sensitive adhesive surface to the other pressure-sensitive adhesive surface, that is, the thickness of the pressure-sensitive adhesive body, and does not include the release liner.
  • the double-sided pressure-sensitive adhesive sheet of the present invention has a 180° peel strength against a stainless steel plate measured at 23°C in a state where a polyethylene terephthalate (PET) film having a thickness of 50 ⁇ m is attached to one adhesive surface, and the peel strength is 20 N/20 mm or more. , preferably 25 N/20 mm or more, more preferably 30 N/20 mm or more.
  • PET polyethylene terephthalate
  • the peel strength is, for example, 50 N/20 mm or less.
  • the 180° peel strength on at least one adhesive surface is preferably within the above range, and more preferably the 180° peel strength on both adhesive surfaces is within the above range.
  • the above peel strength is a value measured with the release liner removed, and the detailed method is as shown in Examples.
  • the double-sided pressure-sensitive adhesive sheet of the present invention is sandwiched between two stainless steel plates, and both adhesive surfaces are bonded together, and the shear adhesive strength to one of the stainless steel plates is measured under the conditions of a tensile speed of 10 mm/min and a peeling angle of 0°. is preferably 1.0 MPa or more, more preferably 1.3 MPa or more, and more preferably 1.5 MPa or more.
  • the shear adhesive strength is 1.0 MPa or more, the adhesiveness when attached to an adherend is excellent.
  • the shear adhesive strength is preferably 10 MPa or less, more preferably 5.0 MPa or less, and even more preferably 3.0 MPa or less.
  • the above peel strength is a value measured with the release liner removed, and the detailed method is as shown in Examples.
  • the double-sided pressure-sensitive adhesive sheet of the present invention preferably has an energy (load x height) of 0.3 or more before one of the stainless steel plates is peeled off, as measured by the following DuPont impact test. Preferably it is 0.4 or more.
  • ⁇ Shock resistance test> A frame-shaped double-sided adhesive sheet with an outer diameter of 24.5 mm square and a width of 2 mm was placed on a stainless steel plate with a hole in the center of a square with an outer diameter of 2 mm and an outer diameter of 50 mm, and a stainless steel plate with a square with an outer diameter of 3 mm and an outer diameter of 25 mm. It is sandwiched between plates and pressed, left to stand in an environment at a temperature of 50° C.
  • the weight and height of the drop weight on the above evaluation sample were changed by 50 mm from 50 to 500 mm at 100 g, changed by 50 mm from 350 to 500 mm at 150 g, and 400 to 500 mm at 200 g.
  • the energy is changed by 50 mm from 350 to 500 mm, and the energy is increased until peeling occurs.
  • the energy that has already been evaluated is not tested, and the load and height are set so that the amount of energy does not overlap. After that, the energy until at least one of the stainless steel plates peels off is calculated by multiplying the load by the height.
  • the double-sided pressure-sensitive adhesive sheet may have a release liner attached to the surface (adhesive surface) of the pressure-sensitive adhesive layer until use.
  • the adhesive surfaces on both sides of the double-sided pressure-sensitive adhesive sheet may be protected by two release liners, respectively, or one release liner having release surfaces on both sides is wound into a roll. It may be protected in a form (wound body).
  • a release liner is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when applied to an adherend. Note that the release liner may not necessarily be provided.
  • a conventional release paper or the like can be used, and is not particularly limited. etc.
  • the base material having the release treatment layer include plastic films and paper surface-treated with release agents such as silicone, long-chain alkyl, fluorine, and molybdenum sulfide.
  • the fluorine-based polymer in the low-adhesive substrate made of the fluorine polymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chloro fluoroethylene-vinylidene fluoride copolymer and the like.
  • the non-polar polymer include olefin resins (eg, polyethylene, polypropylene, etc.).
  • the release liner can be formed by a known or commonly used method. Also, the thickness of the release liner is not particularly limited.
  • the double-sided pressure-sensitive adhesive sheet is preferably for attaching to electrical and electronic members, which is used by being attached to members provided in electrical and electronic equipment.
  • the above-mentioned double-sided pressure-sensitive adhesive sheet is particularly preferably used for bonding parts provided in electrical and electronic equipment to both adhesive surfaces of the double-sided pressure-sensitive adhesive sheet, i.e., for fixing members to each other in electrical and electronic equipment.
  • the double-sided pressure-sensitive adhesive sheet may be used for fixing the members together or temporarily fixing them. For example, when a double-sided adhesive sheet is used for fixing or temporarily fixing parts provided in electrical and electronic equipment, there are cases in which it is necessary to peel off the double-sided adhesive sheet and rework due to a problem in attaching the double-sided adhesive sheet.
  • the double-sided pressure-sensitive adhesive sheet must be peeled off in order to repair, replace, inspect, recycle, or the like a member having an adherend to which the double-sided pressure-sensitive adhesive sheet is attached.
  • the double-sided pressure-sensitive adhesive sheet is used, for example, for fixing or temporarily fixing components provided in an electric/electronic device, the frequency of removing the double-sided pressure-sensitive adhesive sheet is particularly high.
  • the above-mentioned double-sided pressure-sensitive adhesive sheet is preferably used by pasting the outer frames of optical members (especially electrical and electronic devices) together. Therefore, the double-sided pressure-sensitive adhesive sheet can be preferably used even if it has a width of 5 mm or less, preferably 3 mm or less.
  • Electric and electronic equipment refers to equipment that corresponds to at least either electrical equipment or electronic equipment.
  • Examples of the electric/electronic devices include image display devices such as liquid crystal displays, electroluminescence displays, and plasma displays, and mobile electronic devices.
  • Examples of the portable electronic devices include mobile phones, smartphones, tablet computers, notebook computers, and various wearable devices (for example, wrist wear types that are worn on the wrist like wristwatches, clips, straps, etc. that are attached to a part of the body) Modular type to be worn, eyewear type including eyeglass type (monocular type and binocular type, including head-mounted type), clothing type that can be attached to shirts, socks, hats, etc.
  • wearable devices for example, wrist wear types that are worn on the wrist like wristwatches, clips, straps, etc. that are attached to a part of the body
  • Modular type to be worn for example, wrist wear types that are worn on the wrist like wristwatches, clips, straps, etc. that are attached to a part of the body
  • eyewear type including eyeglass type (monocular type and binocular type, including head-mounted type)
  • clothing type that can be attached to shirts, socks, hats, etc.
  • the term “portable” means not only being able to be carried but also having a level of portability that allows individuals (standard adults) to relatively easily carry it. shall mean.
  • the double-sided pressure-sensitive adhesive sheet is used, for example, so that the pressure-sensitive adhesive layer adheres to the member of the portable electronic device.
  • AA cyclohexyl acrylate
  • the resulting acrylic pressure-sensitive adhesive composition was coated on a 38- ⁇ m-thick polyethylene terephthalate film (product name “MRF#38”, manufactured by Mitsubishi Chemical Corporation) whose one side was treated with silicone for release, and the pressure-sensitive adhesive layer thickness was 200 ⁇ m. was applied using an applicator to form a coating layer.
  • MRF#38 polyethylene terephthalate film
  • a 25 ⁇ m-thick polyethylene terephthalate film (product name “MRE #25”, manufactured by Mitsubishi Chemical Corporation) whose one side was release-treated with silicone was coated with the coating layer so that the release-treated surface was on the side of the coating layer. , oxygen was cut off.
  • a black light lamp was used to irradiate ultraviolet rays with an illuminance of 4 mW/cm 2 (UV checker "UVR-T1", manufactured by Topcon Corporation, maximum sensitivity at measurement: about 350 nm) for 180 seconds.
  • a pressure-sensitive adhesive layer having a thickness of 200 ⁇ m was formed to prepare a double-sided pressure-sensitive adhesive sheet.
  • Example 2 A double-sided pressure-sensitive adhesive sheet of Example 2 was produced in the same manner as in Example 1, except that the syrup (2) obtained in Production Example 2 was used in place of the syrup (1) obtained in Production Example 1.
  • Example 3 Syrup (2) obtained in Production Example 2: 100 parts by mass, acrylic acid (AA): 2 parts by mass, black pigment containing carbon black (trade name “Multilac A903", manufactured by Toyocolor Co., Ltd.): 0. 2 parts by mass, polyethylene powder as a filler (trade name “Frick UF-80”, manufactured by Sumitomo Seika Co., Ltd.): 2 parts by mass, 1,6-hexanediol diacrylate (HDDA): 0.12 parts by mass, and 2,2-dimethoxy-1,2-diphenylethan-1-one as a photopolymerization initiator (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.): After blending 0.1 part by mass, disper was applied. It was mixed uniformly using the above, and then defoamed to obtain an acrylic pressure-sensitive adhesive composition.
  • a double-sided pressure-sensitive adhesive sheet of Example 3 was produced in the same manner as in Example 1, except that the acrylic pressure-sensitive adhesive composition obtained above was used.
  • Example 4 Syrup (2) obtained in Production Example 2: 100 parts by mass, cyclohexyl acrylate (CHA): 20 parts by mass, black pigment containing carbon black (trade name "Multilac A903", manufactured by Toyocolor Co., Ltd.): 0.
  • CHA cyclohexyl acrylate
  • Black pigment containing carbon black trade name "Multilac A903", manufactured by Toyocolor Co., Ltd.
  • polyethylene powder as a filler (trade name “Frick UF-80”, manufactured by Sumitomo Seika Co., Ltd.): 2 parts by mass, 1,6-hexanediol diacrylate (HDDA): 0.12 parts by mass, and 2,2-dimethoxy-1,2-diphenylethan-1-one as a photopolymerization initiator (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.): After blending 0.1 part by mass, disper was applied. It was mixed uniformly using the above, and then defoamed to obtain an acrylic pressure-sensitive adhesive composition.
  • HDDA 1,6-hexanediol diacrylate
  • OMNIRAD651 2,2-dimethoxy-1,2-diphenylethan-1-one as a photopolymerization initiator
  • a double-sided pressure-sensitive adhesive sheet of Example 4 was produced in the same manner as in Example 1, except that the acrylic pressure-sensitive adhesive composition obtained above was used.
  • Example 5 A double-sided pressure-sensitive adhesive sheet of Example 5 was produced in the same manner as in Example 1 except that the syrup (3) obtained in Production Example 3 was used in place of the syrup (1) obtained in Production Example 1.
  • Example 6 A double-sided pressure-sensitive adhesive sheet of Example 6 was prepared in the same manner as in Example 1, except that 2 parts by mass of silicone rubber particles (trade name “Torayfil E-606” manufactured by Toray Industries, Inc.) were used as a filler.
  • silicone rubber particles trade name “Torayfil E-606” manufactured by Toray Industries, Inc.
  • Example 7 A double-sided pressure-sensitive adhesive sheet of Example 7 was prepared in the same manner as in Example 1, except that 2 parts by mass of polyethylene particles (trade name “Flobeads FBRP”, manufactured by Sumitomo Seika Chemicals Co., Ltd.) were used as a filler.
  • polyethylene particles trade name “Flobeads FBRP”, manufactured by Sumitomo Seika Chemicals Co., Ltd.
  • a double-sided pressure-sensitive adhesive sheet of Comparative Example 1 was produced in the same manner as in Example 1, except that the acrylic pressure-sensitive adhesive composition obtained above was used.
  • Comparative example 2 Except that the amount of 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.) as a photopolymerization initiator was set to 0.05 parts by mass.
  • a double-sided pressure-sensitive adhesive sheet of Comparative Example 2 was prepared in the same manner as in Comparative Example 1.
  • Comparative example 3 A double-sided pressure-sensitive adhesive sheet of Comparative Example 3 was prepared in the same manner as in Comparative Example 1, except that the syrup (4) obtained in Production Example 4 was used in place of the syrup (2) obtained in Production Example 2.
  • a pressure-sensitive adhesive layer having a thickness of about 2 mm was prepared by stacking a plurality of double-sided pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples. A disk-shaped sample with a diameter of 7.9 mm was punched out of this adhesive layer and fixed by sandwiching it between parallel plates.
  • a Instruments Co., Ltd. was used to perform dynamic viscoelasticity measurement under the following conditions, and storage elastic modulus G' (-20 ° C.), storage elastic modulus G' (23 ° C.), storage elastic modulus G' ( 65° C.), the glass transition temperature, and the peak top value of tan ⁇ were calculated.
  • Measurement mode Shear mode Temperature range: -70°C to 150°C Heating rate: 5°C/min Measurement frequency: 1Hz
  • one adhesive surface 10a of the measurement sample 10 was adhered to a stainless steel plate 21, and the other adhesive surface 10b of the measurement sample 10 was adhered to a stainless steel plate 22 and pressure-bonded. This is pulled in the direction of the arrow in FIG. 2 (that is, shear direction) at the above speed, and the peel strength per 20 mm ⁇ 20 mm is measured. A shear adhesive strength [MPa] was obtained from the obtained value.
  • a tensile tester a universal tension/compression tester (product name “TG-1kN”, manufactured by Minebea Co., Ltd.) was used.
  • a cylindrical measurement table with a length of 50 mm, an outer diameter of 49 mm, and an inner diameter of 43 mm is installed on the pedestal of a DuPont impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and a test piece is placed on it, a square stainless steel plate. (stainless steel plate without holes) was placed on the bottom side.
  • a stainless steel striking core with a tip radius of 3.1 mm is placed on the test piece, and the weight and height of the falling weight are changed by 50 mm from 50 to 500 mm at 100 g, by 50 mm from 350 to 500 mm at 150 g, and then to 200 g.
  • the energy was changed by 50 mm from 400 to 500 mm, and at 300 g by 50 mm from 350 to 500 mm, the energy was increased until peeling occurred. At this time, no test was performed on the energy that had already been evaluated, and the load and height were set so that the amount of energy would not overlap. After that, the energy until at least one of the stainless steel plates peeled off was calculated by multiplying the load by the height, and the result was obtained.
  • the release liner was peeled off from one adhesive surface under a measurement environment of 23°C and 50% RH to form a PET film having a thickness of 50 ⁇ m.
  • a measurement sample was prepared by pasting and lining, and cutting into a size of 25 mm in width and 100 mm in length.
  • the release liner was peeled off from the other adhesive surface of the measurement sample, and the adhesive surface was placed on the surface of a stainless steel plate (SUS304BA plate) with a 2 kg roller. was crimped by reciprocating once.
  • the peel strength was measured using a universal tension/compression tester according to JIS Z0237 (2000) under the conditions of a tensile speed of 300 mm/min and a peel angle of 180°. .
  • a universal tension/compression tester a trade name "Tension/Compression Tester, TG-1kN" (manufactured by Minebea Co., Ltd.) was used.

Abstract

[Problem] To provide a double-sided pressure-sensitive adhesive sheet having excellent impact resistance, high shear adhesive force, and excellent initial tackiness. [Solution] A double-sided pressure-sensitive adhesive sheet 1 includes a pressure-sensitive adhesive layer 2, wherein the pressure-sensitive adhesive layer 2 is an active-ray-curable acrylic pressure-sensitive adhesive layer comprising an acrylic polymer as a base polymer. The acrylic polymer comprises 50 mass% or more constituent units derived from an alkyl (meth)acrylate (A) in which the alkyl group is a linear or branched C2-C7 alkyl. The pressure-sensitive adhesive layer 2 has a glass transition temperature of 0°C or higher, a -20°C storage modulus G' of 10 MPa or greater, and a 65°C storage modulus G' of 0.05 MPa or greater. The double-sided pressure-sensitive adhesive sheet 1 has a 180° peel strength in application to a stainless-steel plate of 20 N/20 mm or greater when examined at 23°C in the state of having a 50 μm-thick poly(ethylene terephthalate) film adherent to one pressure-sensitive adhesive surface thereof.

Description

両面粘着シートdouble-sided adhesive sheet
　本発明は両面粘着シートに関する。 The present invention relates to a double-sided adhesive sheet.
　近年、携帯電話、デジタルカメラ、ＰＤＡ（Ｐｅｒｓｏｎａｌ　Ｄｉｇｉｔａｌ　Ａｓｓｉｓｔａｎｔ）等の携帯機器の小型化が進んでいる。そのため、搭載される各種電子部品についても小型化・薄型化が図られている。例えば、携帯機器として代表的な機器である携帯電話は、構成される主要部品がそれぞれ薄層化される傾向にある。通常、携帯機器の表示部分は、主にＬＣＤモジュールとバックライトユニットとからなり、発光・反射・遮光・導光等の機能を発現させるために、各種シート状の部品が積層されている。そこで、これらの部品の組立て（接合）に用いるための両面粘着シート（両面粘着テープ）が使用されている。 In recent years, mobile devices such as mobile phones, digital cameras, and PDAs (Personal Digital Assistants) are becoming smaller. Therefore, various electronic components mounted thereon are being made smaller and thinner. For example, a mobile phone, which is a typical mobile device, tends to have thinned main components. Usually, the display part of a portable device is mainly composed of an LCD module and a backlight unit, and various sheet-like parts are laminated in order to exhibit functions such as light emission, reflection, light blocking, and light guiding. Therefore, a double-sided adhesive sheet (double-sided adhesive tape) is used for assembling (bonding) these parts.
　例えば、携帯電子機器は、その使用形態により落下の危険に晒されることが多い。このため、携帯電子機器に使用される両面粘着シートには、携帯電子機器の落下の衝撃により、破損したり部品から剥がれたりしにくいように、耐衝撃性が求められる。 For example, portable electronic devices are often exposed to the risk of falling due to their usage patterns. For this reason, double-sided pressure-sensitive adhesive sheets used in portable electronic devices are required to have impact resistance so that they are less likely to be damaged or peeled off from parts due to the impact of dropping the portable electronic device.
　携帯電子機器に使用され、耐衝撃性に優れる両面粘着シートとしては、例えば特許文献１～３に開示のものが知られている。 For example, Patent Documents 1 to 3 disclose, for example, known double-sided pressure-sensitive adhesive sheets that are used in mobile electronic devices and have excellent impact resistance.
特開２０２０－１２８４５３号公報JP 2020-128453 A 特開２０２０－１２８４５４号公報JP 2020-128454 A 特開２０２１－２４９０７号公報Japanese Patent Application Laid-Open No. 2021-24907
　携帯電子機器は、非操作時において様々な衝撃を受けることがあるため、携帯電子機器に使用される両面粘着シートには、被着体の変形による剥離を起こりにくくするために高いせん断接着力を有することが求められる。 Portable electronic devices are subject to various impacts when they are not in operation. Therefore, the double-sided adhesive sheets used for portable electronic devices have high shear adhesive strength to prevent peeling due to deformation of the adherend. required to have
　しかしながら、一般的に、両面粘着シートは粘着剤層が柔軟であると、耐衝撃性に優れる傾向がある一方、せん断接着力が低くなる傾向がある。また、両面粘着シートの粘着剤層が硬いと、せん断接着力が高くなるが、表面の粘着性が低い傾向にあるため、両面粘着シートを被着体に貼り合わせる際の粘着性（初期粘着性）に劣る傾向がある。このため、耐衝撃性に優れ、高いせん断接着力を有し、且つ初期粘着性に優れる両面粘着シートを実現することは困難とされていた。特許文献１～３には、耐衝撃性に優れ、高いせん断接着力を有し、且つ初期粘着性に優れることについては言及されていない。 However, in general, a double-sided PSA sheet with a flexible PSA layer tends to have excellent impact resistance, but tends to have low shear adhesive strength. In addition, if the adhesive layer of the double-sided adhesive sheet is hard, the shear adhesive strength increases, but the adhesiveness of the surface tends to be low. ) tends to be inferior to For this reason, it has been considered difficult to realize a double-faced PSA sheet that has excellent impact resistance, high shear adhesive strength, and excellent initial tackiness. Patent Documents 1 to 3 do not mention excellent impact resistance, high shear adhesive strength, and excellent initial tackiness.
　本発明は、このような事情のもとで考え出されたものであって、その目的は、耐衝撃性に優れ、高いせん断接着力を有し、且つ初期粘着性に優れる両面粘着シートを提供することにある。 The present invention was conceived under such circumstances, and its object is to provide a double-sided pressure-sensitive adhesive sheet having excellent impact resistance, high shear adhesive strength, and excellent initial adhesiveness. to do.
　本発明者らは、上記目的を達成するため鋭意検討した結果、基材を有しない両面粘着シートであって、両面粘着シートを構成する粘着剤層中のベースポリマー組成、当該粘着剤層の２つの温度条件における貯蔵弾性率Ｇ’およびガラス転移温度、ならびに両面粘着シートのステンレス鋼板に対する１８０°剥離強度を特定のものとすることにより、耐衝撃性に優れ、高いせん断接着力を有し、且つ初期粘着性に優れることを見出した。本発明は、これらの知見に基づいて完成されたものである。 As a result of intensive studies to achieve the above object, the present inventors have found that a double-sided pressure-sensitive adhesive sheet having no substrate, a base polymer composition in the pressure-sensitive adhesive layer constituting the double-sided pressure-sensitive adhesive sheet, By specifying the storage elastic modulus G′ and glass transition temperature under two temperature conditions, and the 180° peel strength of the double-sided PSA sheet against a stainless steel plate, it has excellent impact resistance, high shear adhesive strength, and It was found to be excellent in initial adhesiveness. The present invention has been completed based on these findings.
　すなわち、本発明は、粘着剤層からなる両面粘着シートであり、
　上記粘着剤層は、ペースポリマーとしてアクリル系ポリマーを含む活性エネルギー線硬化型のアクリル系粘着剤層であり、
　上記アクリル系ポリマーは、炭素数２～７の直鎖または分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステル（Ａ）に由来する構成単位を５０質量％以上含み、
　上記粘着剤層は、ガラス転移温度が０℃以上であり、－２０℃における貯蔵弾性率Ｇ’が１０ＭＰａ以上、６５℃における貯蔵弾性率Ｇ’が０．０５ＭＰａ以上であり、
　上記両面粘着シートの一方の粘着面に厚さ５０μｍのポリエチレンテレフタレートフィルムを貼り付けた状態での２３℃で測定されるステンレス鋼板に対する１８０°剥離強度は２０Ｎ／２０ｍｍ以上である、両面粘着シートを提供する。 That is, the present invention is a double-sided pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer,
The pressure-sensitive adhesive layer is an active energy ray-curable acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer,
The acrylic polymer contains 50% by mass or more of structural units derived from a (meth)acrylic acid alkyl ester (A) having a linear or branched alkyl group having 2 to 7 carbon atoms,
The pressure-sensitive adhesive layer has a glass transition temperature of 0° C. or higher, a storage elastic modulus G′ of 10 MPa or higher at −20° C., and a storage elastic modulus G′ of 0.05 MPa or higher at 65° C.,
Provided is a double-sided pressure-sensitive adhesive sheet having a 180° peel strength against a stainless steel plate measured at 23°C of 20 N/20 mm or more when a polyethylene terephthalate film having a thickness of 50 µm is attached to one adhesive surface of the double-sided pressure-sensitive adhesive sheet. do.
　上記（メタ）アクリル酸アルキルエステル（Ａ）は（メタ）アクリル酸ブチルを含み、上記アクリル系ポリマー中の（メタ）アクリル酸ブチルに由来する構成単位の割合は５０質量％以上であることが好ましい。 The (meth)acrylic acid alkyl ester (A) contains butyl (meth)acrylate, and the proportion of structural units derived from butyl (meth)acrylate in the acrylic polymer is preferably 50% by mass or more. .
　上記アクリル系ポリマーは、ポリマーを構成するモノマー成分として多官能性モノマーを含むことが好ましい。 The above acrylic polymer preferably contains a polyfunctional monomer as a monomer component that constitutes the polymer.
　上記アクリル系ポリマーは光重合開始剤に由来する構造部を有することが好ましい。 The acrylic polymer preferably has a structural portion derived from a photopolymerization initiator.
　上記アクリル系ポリマーは、ホモポリマーのガラス転移温度が０℃以上であり且つ非芳香族性環を有するモノマー成分（Ｂ）に由来する構成単位を含むことが好ましい。 The above acrylic polymer preferably contains structural units derived from a monomer component (B) having a homopolymer glass transition temperature of 0°C or higher and having a non-aromatic ring.
　上記両面粘着シートは、電気電子機器における部材同士の固定用であることが好ましい。 The double-sided pressure-sensitive adhesive sheet is preferably for fixing members to each other in electrical and electronic equipment.
　また、本発明は、上記両面粘着シートを備え、上記両面粘着シートは両方の粘着面で部材同士を固定している、電気電子機器を提供する。 The present invention also provides an electrical and electronic device comprising the double-sided pressure-sensitive adhesive sheet, wherein both pressure-sensitive adhesive surfaces of the double-sided pressure-sensitive adhesive sheet fix members to each other.
　本発明の両面粘着シートは、耐衝撃性に優れ、高いせん断接着力を有し、且つ初期粘着性に優れる。このため、例えば携帯電子機器に使用した際、部材同士を充分に固定することができ、そして落下衝撃を受けた場合や被着体が変形した場合であっても剥離しにくい。 The double-sided pressure-sensitive adhesive sheet of the present invention has excellent impact resistance, high shear adhesive strength, and excellent initial adhesiveness. Therefore, when used in, for example, a portable electronic device, the members can be sufficiently fixed to each other, and even when the adherend is subjected to a drop impact or the adherend is deformed, it is difficult to peel off.
本発明の一実施形態に係る両面粘着シートの断面模式図である。BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram of the double-sided adhesive sheet which concerns on one Embodiment of this invention. せん断接着力の測定方法を模式的に示す説明図である。It is explanatory drawing which shows typically the measuring method of a shear adhesive strength.
［両面粘着シート］
　本発明の両面粘着シートは、粘着剤層からなる両面粘着シートであり、基材を有しないいわゆる「基材レス」の両面粘着シートである。 [Double-sided adhesive sheet]
The double-sided pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer, and is a so-called "substrate-less" double-sided pressure-sensitive adhesive sheet that does not have a substrate.
　上記粘着剤層は、ペースポリマーとしてアクリル系ポリマーを含む活性エネルギー線硬化型のアクリル系粘着剤層であり、ガラス転移温度が０℃以上であり、－２０℃における貯蔵弾性率Ｇ’が１０ＭＰａ以上、６５℃における貯蔵弾性率Ｇ’が０．０５ＭＰａ以上である。上記アクリル系粘着剤層に含まれるアクリル系ポリマーは、炭素数２～７の直鎖または分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステルに由来する構成単位を５０質量％以上含む。本明細書において、上記粘着剤層を「本発明の粘着剤層」と称する場合がある。 The pressure-sensitive adhesive layer is an active energy ray-curable acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer, has a glass transition temperature of 0° C. or higher, and a storage elastic modulus G′ at −20° C. of 10 MPa or higher. , and a storage modulus G′ at 65° C. of 0.05 MPa or more. The acrylic polymer contained in the acrylic pressure-sensitive adhesive layer contains 50% by mass or more of structural units derived from a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 2 to 7 carbon atoms. In this specification, the pressure-sensitive adhesive layer may be referred to as "the pressure-sensitive adhesive layer of the present invention".
　本発明の両面粘着シートを構成する上記粘着剤層は、単層であってもよいし、複層であってもよい。本発明の両面粘着シートが複数の粘着剤層から構成される場合、当該複数の粘着剤層はいずれも本発明の粘着剤層である。上記複数の粘着剤層は、同一の粘着剤層であってもよく、組成、厚さ、物性などが異なる粘着剤層であってもよい。 The pressure-sensitive adhesive layer constituting the double-sided pressure-sensitive adhesive sheet of the present invention may be a single layer or multiple layers. When the double-sided pressure-sensitive adhesive sheet of the present invention is composed of a plurality of pressure-sensitive adhesive layers, each of the plurality of pressure-sensitive adhesive layers is the pressure-sensitive adhesive layer of the present invention. The plurality of pressure-sensitive adhesive layers may be the same pressure-sensitive adhesive layer, or may be pressure-sensitive adhesive layers having different compositions, thicknesses, physical properties, and the like.
　図１は、本発明の両面粘着シートの一実施形態を示す断面模式図である。図１に示すように、両面粘着シート１は、本発明の粘着剤層２単層で構成される。粘着剤層２の粘着面には、それぞれ、はく離ライナー３および４が貼り合わせられている。 FIG. 1 is a schematic cross-sectional view showing one embodiment of the double-sided pressure-sensitive adhesive sheet of the present invention. As shown in FIG. 1, a double-sided pressure-sensitive adhesive sheet 1 is composed of a single pressure-sensitive adhesive layer 2 of the present invention. Release liners 3 and 4 are attached to the adhesive surfaces of the adhesive layer 2, respectively.
（本発明の粘着剤層）
　本発明の粘着剤層は、粘着性を発揮するベースポリマーとしてアクリル系ポリマーを含むアクリル系粘着剤層である。なお、本明細書において、ベースポリマーとは、粘着剤層を構成する粘着剤におけるポリマー成分の中の主成分、例えば５０質量％を超えて含まれるポリマー成分をいうものとする。 (Adhesive layer of the present invention)
The pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer exhibiting adhesiveness. In this specification, the base polymer refers to a main component among the polymer components in the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, for example, a polymer component contained in an amount exceeding 50% by mass.
　上記粘着剤層中のベースポリマーの割合は、粘着剤層の総量１００質量％に対して、６０質量％以上が好ましく、より好ましくは７０質量％以上である。 The proportion of the base polymer in the pressure-sensitive adhesive layer is preferably 60% by mass or more, more preferably 70% by mass or more, relative to 100% by mass of the total amount of the pressure-sensitive adhesive layer.
　上記アクリル系ポリマーは、ポリマーを構成するモノマー成分として、アクリル系モノマー（分子中に（メタ）アクリロイル基を有するモノマー）を含むポリマーである。すなわち、上記アクリル系ポリマーは、アクリル系モノマーに由来する構成単位を含む。なお、アクリル系ポリマーは、一種のみを使用してもよいし、二種以上を使用してもよい。また、上記アクリル系ポリマーは、モノマー成分としてアクリル系モノマーを一種のみを含んでいてもよいし、二種以上を含んでいてもよい。なお、本明細書において、「（メタ）アクリル」とは、「アクリル」および／または「メタクリル」（「アクリル」および「メタクリル」のうち、いずれか一方または両方）を表し、他も同様である。 The above acrylic polymer is a polymer containing an acrylic monomer (a monomer having a (meth)acryloyl group in the molecule) as a monomer component that constitutes the polymer. That is, the acrylic polymer contains structural units derived from acrylic monomers. In addition, acrylic polymer may use only 1 type, and may use 2 or more types. Moreover, the said acrylic polymer may contain only 1 type of acrylic monomers as a monomer component, and may contain 2 or more types. In the present specification, "(meth)acrylic" means "acrylic" and/or "methacrylic" (one or both of "acrylic" and "methacrylic"), and the same applies to others. .
　上記アクリル系ポリマーは、炭素数２～７の直鎖または分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステル（「（メタ）アクリル酸アルキルエステル（Ａ）」と称する場合がある）を必須のモノマー成分として構成（形成）された重合体である。すなわち、上記アクリル系ポリマーは、構成単位として、（メタ）アクリル酸アルキルエステル（Ａ）を含む。上記アクリル系ポリマーは、モノマー成分として（メタ）アクリル酸アルキルエステル（Ａ）を一種のみを含んでいてもよいし、二種以上を含んでいてもよい。 The acrylic polymer is a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 2 to 7 carbon atoms (sometimes referred to as "(meth)acrylic acid alkyl ester (A)"). It is a polymer composed (formed) as an essential monomer component. That is, the acrylic polymer contains a (meth)acrylic acid alkyl ester (A) as a structural unit. The acrylic polymer may contain only one type of (meth)acrylic acid alkyl ester (A) as a monomer component, or may contain two or more types.
　（メタ）アクリル酸アルキルエステル（Ａ）としては、特に限定されないが、例えば、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｓ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸ペンチル、（メタ）アクリル酸イソペンチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸ヘプチルなどが挙げられる。中でも、より低い貯蔵弾性率Ｇ‘を選定するという観点から、（メタ）アクリル酸ブチルが好ましい。 The (meth)acrylic acid alkyl ester (A) is not particularly limited, but examples thereof include ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, Isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic and heptyl acid. Among them, butyl (meth)acrylate is preferable from the viewpoint of selecting a lower storage elastic modulus G'.
　上記アクリル系ポリマーを構成する全モノマー成分の総量１００質量％中の、（メタ）アクリル酸アルキルエステル（Ａ）の割合は、５０質量％以上であり、好ましくは６０質量％以上、より好ましくは６５質量％以上である。上記割合が５０質量％以上であることにより、薄くても良好な密着性を有する粘着剤層を形成可能となる。上記割合は、９４質量％以下が好ましく、より好ましくは９０質量％以下、さらに好ましくは８５質量％以下である。また、（メタ）アクリル酸ブチルの割合が上記範囲内であることが好ましい。 The proportion of the (meth)acrylic acid alkyl ester (A) in 100% by mass of the total amount of all monomer components constituting the acrylic polymer is 50% by mass or more, preferably 60% by mass or more, more preferably 65% by mass. % by mass or more. When the above ratio is 50% by mass or more, it is possible to form a pressure-sensitive adhesive layer having good adhesiveness even if it is thin. The proportion is preferably 94% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. Moreover, it is preferable that the ratio of butyl (meth)acrylate is within the above range.
　上記アクリル系ポリマーは、（メタ）アクリル酸アルキルエステル（Ａ）とともに、ホモポリマーのガラス転移温度が０℃以上であり且つ非芳香族性環を有するモノマー成分（「モノマー成分（Ｂ）」と称する場合がある）をモノマー成分として構成（形成）された重合体であることが好ましい。上記アクリル系ポリマーは、モノマー成分としてモノマー成分（Ｂ）を一種のみを含んでいてもよいし、二種以上を含んでいてもよい。 The acrylic polymer, together with the (meth)acrylic acid alkyl ester (A), is a monomer component having a homopolymer glass transition temperature of 0 ° C. or higher and having a non-aromatic ring (referred to as "monomer component (B)" It is preferably a polymer constituted (formed) as a monomer component. The acrylic polymer may contain only one monomer component (B) as a monomer component, or may contain two or more monomer components.
　上記非芳香族性環としては、非芳香族性炭化水素環および非芳香族性複素環が挙げられる。上記非芳香族性環は飽和または不飽和のいずれであってもよい。上記非芳香族性炭化水素族環としては、脂肪族炭化水素環が挙げられ、例えば、シクロペンタン環、シクロヘキサン環、シクロヘプタン環、シクロオクタン環などのシクロアルカン環；シクロヘキセン環などのシクロアルケン環；二環式炭化水素環や三環以上の脂肪族炭化水素環などの橋かけ式炭化水素環が挙げられる。二環式炭化水素環としては、ピナン環、ピネン環、ボルナン環、ノルボルナン環、ノルボルネン環などが挙げられる。三環以上の脂肪族炭化水素環（三環以上の橋かけ式炭化水素環）としては、例えば、ジシクロペンタン環、ジシクロペンテン環、アダマンタン環、トリシクロペンタン環、トリシクロペンテン環などが挙げられる。 The non-aromatic ring includes a non-aromatic hydrocarbon ring and a non-aromatic heterocyclic ring. The non-aromatic ring may be either saturated or unsaturated. Examples of the non-aromatic hydrocarbon ring include aliphatic hydrocarbon rings such as cycloalkane rings such as cyclopentane ring, cyclohexane ring, cycloheptane ring and cyclooctane ring; cycloalkene rings such as cyclohexene ring; bridging hydrocarbon rings such as bicyclic hydrocarbon rings and tricyclic or higher aliphatic hydrocarbon rings; Bicyclic hydrocarbon rings include pinane ring, pinene ring, bornane ring, norbornane ring, norbornene ring and the like. Tricyclic or higher aliphatic hydrocarbon rings (tricyclic or higher bridged hydrocarbon rings) include, for example, dicyclopentane ring, dicyclopentene ring, adamantane ring, tricyclopentane ring, tricyclopentene ring and the like. .
　上記非芳香族性複素環としては、酸素原子含有複素環、窒素原子含有複素環、硫黄原子含有複素環などが挙げられる。酸素原子含有複素環としては、オキソラン環、オキサン環、オキソール環、ピラン環、カプロラクトン環、カプロラクタム環、酸素原子および窒素原子を含む複素環などが挙げられる。窒素原子含有複素環としては、アゾリジン環、アジナン環、アゾール環、ピペリジン環、カプロラクタム環、酸素原子および窒素原子を含む複素環、窒素原子および硫黄原子を含む複素環などが挙げられる。硫黄原子含有複素環としては、チオラン環、チオール環、窒素原子および硫黄原子を含む複素環などが挙げられる。酸素原子および窒素原子を含む複素環としては、モルホリン環などが挙げられる。窒素原子および硫黄原子を含む複素環としては、チアジン環、チアゾール環などが挙げられる。 Examples of the non-aromatic heterocyclic ring include an oxygen atom-containing heterocyclic ring, a nitrogen atom-containing heterocyclic ring, a sulfur atom-containing heterocyclic ring, and the like. The oxygen atom-containing heterocyclic ring includes oxolane ring, oxane ring, oxole ring, pyran ring, caprolactone ring, caprolactam ring, heterocyclic ring containing oxygen atom and nitrogen atom, and the like. The nitrogen atom-containing heterocyclic ring includes azolidine ring, azinane ring, azole ring, piperidine ring, caprolactam ring, heterocyclic ring containing oxygen atom and nitrogen atom, heterocyclic ring containing nitrogen atom and sulfur atom, and the like. The sulfur atom-containing heterocyclic ring includes thiolane ring, thiol ring, heterocyclic ring containing nitrogen atom and sulfur atom, and the like. A heterocyclic ring containing an oxygen atom and a nitrogen atom includes a morpholine ring and the like. A heterocyclic ring containing a nitrogen atom and a sulfur atom includes a thiazine ring, a thiazole ring, and the like.
　上記非芳香族性環における環を構成する原子数は、５～１２が好ましく、より好ましくは６～１０である。また、モノマー成分（Ｂ）は活性エネルギー線重合性を有する炭素－炭素二重結合（例えば、（メタ）アクリロイル基、ビニル基など）と非芳香族性環を有するモノマー成分であることが好ましく、エステル部分に非芳香族性環を有する（メタ）アクリル酸エステルや、ビニル基と非芳香族性複素環とを有するモノマー成分などが挙げられる。上記（メタ）アクリル酸エステルにおいて、上記非芳香族性環は、（メタ）アクリロイル基と直接結合しているか、または、酸素原子もしくはオキシアルキレン基を介して（メタ）アクリロイル基と結合していることが好ましい。上記非芳香族性環としては、中でも、脂肪族炭化水素環、窒素原子含有複素環が好ましい。 The number of atoms constituting the non-aromatic ring is preferably 5-12, more preferably 6-10. Further, the monomer component (B) is preferably a monomer component having a carbon-carbon double bond (e.g., (meth)acryloyl group, vinyl group, etc.) having active energy ray polymerizability and a non-aromatic ring. Examples thereof include (meth)acrylic acid esters having a non-aromatic ring in the ester portion, and monomer components having a vinyl group and a non-aromatic heterocyclic ring. In the (meth)acrylic acid ester, the non-aromatic ring is directly bonded to the (meth)acryloyl group, or bonded to the (meth)acryloyl group via an oxygen atom or an oxyalkylene group. is preferred. As the non-aromatic ring, among others, an aliphatic hydrocarbon ring and a nitrogen atom-containing heterocyclic ring are preferable.
　非芳香族性環が脂肪族炭化水素環であるモノマー成分（Ｂ）としては、具体的には、例えば、（メタ）アクリル酸シクロペンチル、（メタ）アクリル酸シクロヘキシル、（メタ）アクリル酸シクロヘプチル、（メタ）アクリル酸シクロオクチルなどの（メタ）アクリル酸シクロアルキルエステル；（メタ）アクリル酸イソボルニルなどの二環式の脂肪族炭化水素環を有する（メタ）アクリル酸エステル；ジシクロペンタニル（メタ）アクリレート、ジシクロペンタニルオキシエチル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、ジシクロペンテニルオキシエチル（メタ）アクリレート、トリシクロペンタニル（メタ）アクリレート、１－アダマンチル（メタ）アクリレート、２－メチル－２－アダマンチル（メタ）アクリレート、２－エチル－２－アダマンチル（メタ）アクリレートなどの三環以上の脂肪族炭化水素環を有する（メタ）アクリル酸エステルなどが挙げられる。 Specific examples of the monomer component (B) in which the non-aromatic ring is an aliphatic hydrocarbon ring include, for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, (Meth)acrylic acid cycloalkyl ester such as cyclooctyl (meth)acrylate; (meth)acrylic acid ester having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; dicyclopentanyl (meth) ) acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2 -Methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, and the like (meth)acrylic acid esters having a tricyclic or higher aliphatic hydrocarbon ring.
　非芳香族性環が窒素原子含有複素環であるモノマー成分（Ｂ）としては、具体的には、例えば、Ｎ－（メタ）アクリロイルモルホリン、Ｎ－ビニル－２－ピロリドン、Ｎ－ビニル－２－ピペリドン、Ｎ－ビニル－３－モルホリノン、Ｎ－ビニル－２－カプロラクタム、Ｎ－ビニル－１，３－オキサジン－２－オン、Ｎ－ビニル－３，５－モルホリンジオン、Ｎ－ビニルピペラジン、Ｎ－ビニルピラジン、Ｎ－ビニルモルホリン、Ｎ－ビニルピラゾール、ビニルピリミジン、２－ビニル－２－オキサゾリン、２－ビニル－５－メチル－２－オキサゾリン、２－イソプロペニル－２－オキサゾリン、ビニルピリダジン、（メタ）アクリロイルピロリドン、（メタ）アクリロイルピロリジン、（メタ）アクリロイルピペリジンなどが挙げられる。 Specific examples of the monomer component (B) in which the non-aromatic ring is a nitrogen atom-containing heterocyclic ring include N-(meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, N-vinyl-2- piperidone, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, N-vinylpiperazine, N- Vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyrimidine, 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, vinylpyridazine, (meth ) acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine and the like.
　モノマー成分（Ｂ）のホモポリマーのＴｇは、０℃以上であり、好ましくは１０℃以上、より好ましくは６０℃以上である。上記Ｔｇが０℃以上であることにより、初期粘着性に優れながら、貯蔵弾性率Ｇ’が高くなり、耐衝撃性により優れる。上記Ｔｇは、初期粘着性により優れる観点から、５０℃以下が好ましく、より好ましくは２０℃以下である。 The Tg of the homopolymer of the monomer component (B) is 0°C or higher, preferably 10°C or higher, more preferably 60°C or higher. When the Tg is 0° C. or more, the storage elastic modulus G′ is increased while the initial adhesiveness is excellent, and the impact resistance is excellent. The Tg is preferably 50° C. or lower, more preferably 20° C. or lower, from the viewpoint of superior initial adhesiveness.
　なお、本明細書における「ホモポリマーを形成した際のガラス転移温度（Ｔｇ）」（単に「ホモポリマーのＴｇ」と称する場合がある）とは、「当該モノマーの単独重合体のガラス転移温度（Ｔｇ）」を意味し、具体的には、「Ｐｏｌｙｍｅｒ　Ｈａｎｄｂｏｏｋ」（第３版、Ｊｏｈｎ　Ｗｉｌｅｙ＆Ｓｏｎｓ，Ｉｎｃ、１９８７年）に数値が挙げられている。なお、上記文献に記載されていないモノマーのホモポリマーのＴｇは、例えば、以下の測定方法により得られる値（特開２００７－５１２７１号公報参照）をいう。すなわち、温度計、撹拌機、窒素導入管、および還流冷却管を備えた反応器に、モノマー１００質量部、２，２’－アゾビスイソブチロニトリル０．２質量部および重合溶媒として酢酸エチル２００質量部を投入し、窒素ガスを導入しながら１時間撹拌する。このようにして重合系内の酸素を除去した後、６３℃に昇温し１０時間反応させる。次いで、室温まで冷却し、固形分濃度３３質量％のホモポリマー溶液を得る。次いで、このホモポリマー溶液をはく離ライナー上に流延塗布し、乾燥して厚さ約２ｍｍの試験サンプル（シート状のホモポリマー）を作製する。そして、この試験サンプルを直径７．９ｍｍの円盤状に打ち抜き、パラレルプレートで挟み込み、粘弾性試験機（商品名「ＡＲＥＳ」、レオメトリックス社製）を用いて周波数１Ｈｚの剪断歪を与えながら、温度領域－７０～１５０℃、５℃／分の昇温速度で剪断モードにより粘弾性を測定し、ｔａｎδのピークトップ温度をホモポリマーのＴｇとする。 In this specification, the "glass transition temperature (Tg) when forming a homopolymer" (sometimes simply referred to as "Tg of the homopolymer") means "the glass transition temperature of the homopolymer of the monomer ( Tg)", specifically, numerical values are listed in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1987). The Tg of a homopolymer of a monomer not described in the above literature refers to, for example, a value obtained by the following measuring method (see JP-A-2007-51271). That is, a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser was charged with 100 parts by mass of a monomer, 0.2 parts by mass of 2,2'-azobisisobutyronitrile and ethyl acetate as a polymerization solvent. 200 parts by mass are added and stirred for 1 hour while nitrogen gas is introduced. After oxygen is removed from the polymerization system in this manner, the temperature is raised to 63° C. and the reaction is allowed to proceed for 10 hours. Then, it is cooled to room temperature to obtain a homopolymer solution having a solid concentration of 33% by mass. The homopolymer solution is then cast onto a release liner and dried to form a test sample (sheet homopolymer) having a thickness of about 2 mm. Then, this test sample was punched out into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear strain at a frequency of 1 Hz using a viscoelasticity tester (trade name “ARES”, manufactured by Rheometrics Co., Ltd.). The viscoelasticity is measured in the shear mode at a heating rate of 5°C/min in the region of -70 to 150°C, and the peak top temperature of tan δ is defined as the Tg of the homopolymer.
　上記アクリル系ポリマーを構成する全モノマー成分の総量１００質量％中の、モノマー成分（Ｂ）の割合は、５質量％以上が好ましく、より好ましくは１０質量％以上、さらに好ましくは１５質量％以上である。上記割合が５質量％以上であると、貯蔵弾性率Ｇ’（特に、－２０℃における貯蔵弾性率Ｇ’）が高くなり、耐衝撃性により優れるモノマー成分（Ｂ）の割合は、６０質量％以下が好ましく、より好ましくは５０質量％以下、さらに好ましくは４０質量％以下である。上記割合が６０質量％以下であると、柔軟性が向上し、被着体に対する密着性やせん断接着力を向上させることができる。 The ratio of the monomer component (B) in the total amount of 100% by mass of all the monomer components constituting the acrylic polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more. be. When the above ratio is 5% by mass or more, the storage elastic modulus G′ (particularly, the storage elastic modulus G′ at −20° C.) is high, and the ratio of the monomer component (B), which is excellent in impact resistance, is 60% by mass. The following is preferable, more preferably 50% by mass or less, and still more preferably 40% by mass or less. When the above ratio is 60% by mass or less, the flexibility is improved, and the adhesiveness to the adherend and the shear adhesive strength can be improved.
　上記アクリル系ポリマーは、ポリマーを構成するモノマー成分として、（メタ）アクリル酸アルキルエステル（Ａ）およびモノマー成分（Ｂ）とともに、共重合性モノマーを含んでいてもよい。すなわち、上記アクリル系ポリマーは、構成単位として、共重合性モノマーを含んでいてもよい。上記共重合性モノマーは、一種のみを使用してもよいし、二種以上を使用してもよい。 The acrylic polymer may contain a copolymerizable monomer together with the (meth)acrylic acid alkyl ester (A) and the monomer component (B) as a monomer component constituting the polymer. That is, the acrylic polymer may contain a copolymerizable monomer as a structural unit. The above copolymerizable monomers may be used alone or in combination of two or more.
　上記共重合性モノマーとしては、薄くても良好な密着性を有する粘着剤層を形成可能であり、また凝集力が向上し耐衝撃性により優れる観点から、カルボキシ基含有モノマーおよび／または酸無水物モノマーが好ましい。上記カルボキシ基含有モノマーとしては、例えば、アクリル酸、メタクリル酸、カルボキシエチル（メタ）アクリレート、カルボキシペンチル（メタ）アクリレート、イタコン酸、マレイン酸、フマル酸、クロトン酸などが挙げられる。上記酸無水物モノマーとしては、例えば、無水マレイン酸、無水イタコン酸などが挙げられる。 As the copolymerizable monomer, a carboxy group-containing monomer and/or an acid anhydride can be used to form a pressure-sensitive adhesive layer having good adhesiveness even if it is thin, and from the viewpoint of improving cohesion and improving impact resistance. Monomers are preferred. Examples of the carboxy group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride monomer include maleic anhydride and itaconic anhydride.
　上記アクリル系ポリマーを構成する全モノマー成分の総量１００質量％中の、カルボキシ基含有モノマーおよび／または酸無水物モノマーの割合は、特に限定されないが、０．２質量％以上であることが好ましく、より好ましくは１質量％以上、さらに好ましくは５質量％以上である。上記割合は、２０質量％以下が好ましく、より好ましくは１５質量％以下、さらに好ましくは１０質量％以下である。上記割合が上記範囲内であると、（メタ）アクリル酸アルキルエステル（Ａ）およびモノマー成分（Ｂ）との量的なバランスが良く、耐衝撃性に優れつつ、薄くても良好な密着性を有する粘着剤層を形成可能となる。 The ratio of the carboxy group-containing monomer and/or the acid anhydride monomer in the total amount of 100% by mass of all the monomer components constituting the acrylic polymer is not particularly limited, but is preferably 0.2% by mass or more, More preferably 1% by mass or more, still more preferably 5% by mass or more. The proportion is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. When the above ratio is within the above range, the quantitative balance between the (meth)acrylic acid alkyl ester (A) and the monomer component (B) is good, and the impact resistance is excellent, and good adhesion is achieved even if the thickness is thin. It becomes possible to form a pressure-sensitive adhesive layer having
　上記共重合性モノマーとしては、さらに、アクリル系ポリマーに架橋点を導入したり、アクリル系ポリマーの凝集力を高めたりする目的で、官能基含有モノマーを含んでいてもよい。上記官能基含有モノマーとしては、ヒドロキシ基含有モノマー、窒素原子含有モノマー（但し、モノマー成分（Ｂ）に該当するものを除く）、ケト基含有モノマー、アルコキシシリル基含有モノマー、スルホン酸基含有モノマー、リン酸基含有モノマーなどが挙げられる。上記官能基含有モノマーは、一種のみを使用してもよいし、二種以上を使用してもよい。 The copolymerizable monomer may further contain a functional group-containing monomer for the purpose of introducing a cross-linking point into the acrylic polymer or increasing the cohesion of the acrylic polymer. Examples of the functional group-containing monomers include hydroxyl group-containing monomers, nitrogen atom-containing monomers (excluding those corresponding to the monomer component (B)), keto group-containing monomers, alkoxysilyl group-containing monomers, sulfonic acid group-containing monomers, Examples include phosphoric acid group-containing monomers. Only one kind of the functional group-containing monomer may be used, or two or more kinds thereof may be used.
　上記ヒドロキシ基含有モノマーとしては、例えば、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸３－ヒドロキシプロピル、（メタ）アクリル酸４－ヒドロキシブチル、（メタ）アクリル酸６－ヒドロキシヘキシル、（メタ）アクリル酸８－ヒドロキシオクチル、（メタ）アクリル酸１０－ヒドロキシデシル、（メタ）アクリル酸１２－ヒドロキシラウリル、（４－ヒドロキシメチルシクロヘキシル）メチル（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート；ビニルアルコール、アリルアルコール等の不飽和アルコール類；ポリプロピレングリコールモノ（メタ）アクリレートなどが挙げられる。 Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) ) hydroxyalkyl (meth)acrylates such as acrylates; unsaturated alcohols such as vinyl alcohol and allyl alcohol; polypropylene glycol mono(meth)acrylates;
　上記窒素原子含有モノマーとしては、例えば、アミド基含有モノマー、アミノ基含有モノマー、シアノ基含有モノマーなどが挙げられる。上記アミド基含有モノマーとしては、例えば（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ－ブチル（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド、Ｎ－メチロールプロパン（メタ）アクリルアミド、Ｎ－メトキシメチル（メタ）アクリルアミド、Ｎ－ブトキシメチル（メタ）アクリルアミドなどが挙げられる。上記アミノ基含有モノマーとしては、例えば、アミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、ｔ－ブチルアミノエチル（メタ）アクリレートなどが挙げられる。上記シアノ基含有モノマーとしては、例えば、アクリロニトリル、メタクリロニトリルが挙げられる。 Examples of the nitrogen atom-containing monomers include amide group-containing monomers, amino group-containing monomers, and cyano group-containing monomers. Examples of the amide group-containing monomer include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N -Methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide and the like. Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate and the like. Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.
　上記ケト基含有モノマーとしては、例えば、ジアセトン（メタ）アクリルアミド、ジアセトン（メタ）アクリレート、ビニルメチルケトン、ビニルエチルケトン、アリルアセトアセテート、ビニルアセトアセテートなどが挙げられる。 Examples of the keto group-containing monomer include diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, and vinyl acetoacetate.
　上記アルコキシシリル基含有モノマーとしては、例えば、３－（メタ）アクリロキシプロピルトリメトキシシラン、３－（メタ）アクリロキシプロピルトリエトキシシラン、３－（メタ）アクリロキシプロピルメチルジメトキシシラン、３－（メタ）アクリロキシプロピルメチルジエトキシシランなどが挙げられる。 Examples of the alkoxysilyl group-containing monomer include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-( meth)acryloxypropylmethyldiethoxysilane and the like.
　上記スルホン酸基含有モノマーとしては、例えば、スチレンスルホン酸、アリルスルホン酸、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、（メタ）アクリルアミドプロパンスルホン酸、スルホプロピル（メタ）アクリレート、（メタ）アクリロイルオキシナフタレンスルホン酸などが挙げられる。 Examples of the sulfonic acid group-containing monomer include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth) ) acryloyloxynaphthalenesulfonic acid and the like.
　上記リン酸基含有モノマーとしては、例えば、２－ヒドロキシエチルアクリロイルホスフェートなどが挙げられる。 Examples of the phosphoric acid group-containing monomer include 2-hydroxyethyl acryloyl phosphate.
　上記アクリル系ポリマーを構成する全モノマー成分の総量１００質量％中の、上記官能基含有モノマーの割合は、例えば、０．１質量％以上、０．５質量％以上、１質量％以上、５質量％以上、１０質量％以上であってもよい。上記割合は、例えば、４０質量％以下、２０質量％以下であってもよく、実質的に含まなくてもよい。なお、本明細書において、実質的に含まないとは、積極的な配合を行うのではなく、不可避に混入する場合など、非意図的に含まれることをいい、例えば０．０５質量％以下、０．０１質量％以下である。 The ratio of the functional group-containing monomer in the total amount of 100% by mass of all the monomer components constituting the acrylic polymer is, for example, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 5% by mass. % or more, or 10% by mass or more. The above ratio may be, for example, 40% by mass or less, 20% by mass or less, or may be substantially absent. In the present specification, the term "substantially not included" refers to unintentional inclusion, such as unavoidable mixing, rather than active blending. It is 0.01% by mass or less.
　上記共重合性モノマーとしては、さらに、その他のモノマーを含んでいてもよい。上記その他のモノマーとしては、例えば、酢酸ビニル、プロピオン酸ビニル、ラウリン酸ビニル等のビニルエステル系モノマー；スチレン、置換スチレン（α－メチルスチレン等）、ビニルトルエン等の芳香族ビニル化合物；エチレン、プロピレン、イソプレン、ブタジエン、イソブチレン等のオレフィン系モノマー；塩化ビニル、塩化ビニリデン等の塩素含有モノマー；２－（メタ）アクリロイルオキシエチルイソシアネート等のイソシアネート基含有モノマー；メトキシエチル（メタ）アクリレート、エトキシエチル（メタ）アクリレート等のアルコキシ基含有モノマー；メチルビニルエーテル、エチルビニルエーテル等のビニルエーテル系モノマー；（メタ）アクリル酸メチル；（メタ）アクリル酸オクチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸イソオクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸イソノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸イソデシル、（メタ）アクリル酸ウンデシル、（メタ）アクリル酸ドデシル（ラウリル（メタ）アクリレート）、（メタ）アクリル酸トリデシル、（メタ）アクリル酸テトラデシル、（メタ）アクリル酸ペンタデシル、（メタ）アクリル酸ヘキサデシル、（メタ）アクリル酸ヘプタデシル、（メタ）アクリル酸オクタデシル（ステアリル（メタ）アクリレート）、イソステアリル（メタ）アクリレート、（メタ）アクリル酸ノナデシル、（メタ）アクリル酸エイコシル等の炭素数が８～２０の直鎖または分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステル；（メタ）アクリル酸フェニル等の（メタ）アクリル酸アリールエステル、（メタ）アクリル酸フェノキシエチル等の（メタ）アクリル酸アリールオキシアルキルエステル、（メタ）アクリル酸ベンジル等の（メタ）アクリル酸アリールアルキルエステルなどの芳香族性環を有する（メタ）アクリル酸エステルなどが挙げられる。 The copolymerizable monomer may further contain other monomers. Examples of the other monomers include vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate; aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene, etc.), and vinyl toluene; ethylene, propylene. , isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; isocyanate group-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate; methoxyethyl (meth)acrylate, ethoxyethyl (meth ) alkoxy group-containing monomers such as acrylate; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; methyl (meth) acrylate; octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, Nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), ( meth)tridecyl acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), isostearyl (Meth)acrylic acid alkyl ester having a linear or branched alkyl group having 8 to 20 carbon atoms, such as (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate; (meth)acrylic Fragrances such as (meth)acrylic acid aryl esters such as phenyl acid, (meth)acrylic acid aryloxyalkyl esters such as phenoxyethyl (meth)acrylate, and (meth)acrylic acid arylalkyl esters such as benzyl (meth)acrylate (Meth)acrylic acid esters having a cyclic ring, and the like.
　上記アクリル系ポリマーを構成する全モノマー成分の総量１００質量％中の、上記その他のモノマーの割合は、例えば、０．０５質量％以上、０．５質量％以上であってもよい。上記割合は、例えば、２０質量％以下、１０質量％以下、５質量％以下であってもよく、実質的に含まなくてもよい。 The proportion of the other monomers in the total amount of 100% by mass of all monomer components constituting the acrylic polymer may be, for example, 0.05% by mass or more, or 0.5% by mass or more. The above ratio may be, for example, 20% by mass or less, 10% by mass or less, 5% by mass or less, or may be substantially absent.
　上記アクリル系ポリマーは、そのポリマー骨格中に架橋構造を形成するために、ポリマーを構成するモノマー成分として、アクリル系ポリマーを形成するモノマー成分と共重合可能な多官能性モノマーを含んでいてもよい。上記多官能性モノマーとしては、例えば、ヘキサンジオールジ（メタ）アクリレート、（ポリ）エチレングリコールジ（メタ）アクリレート、（ポリ）プロピレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート等の多官能（メタ）アクリレート；エポキシ（メタ）アクリレート（例えば、ポリグリシジル（メタ）アクリレート）、ポリエステル（メタ）アクリレート、ウレタン（メタ）アクリレート等の分子内に（メタ）アクリロイル基と他の反応性官能基を有する単量体などが挙げられる。上記多官能性モノマーは、一種のみを使用してもよいし、二種以上を使用してもよい。 The acrylic polymer may contain, as a monomer component constituting the polymer, a polyfunctional monomer copolymerizable with the monomer component forming the acrylic polymer, in order to form a crosslinked structure in the polymer skeleton. . Examples of the polyfunctional monomer include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, penta Polyfunctional (meth)acrylates such as erythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate; epoxy (meth)acrylates (e.g., poly glycidyl (meth)acrylate), polyester (meth)acrylate, urethane (meth)acrylate, and other monomers having a (meth)acryloyl group and other reactive functional groups in the molecule. Only one kind of the polyfunctional monomer may be used, or two or more kinds thereof may be used.
　上記アクリル系ポリマーを構成する全モノマー成分の総量１００質量％中の、上記多官能性モノマーの割合は、０．０５質量％以上が好ましく、より好ましくは０．０７質量％、さらに好ましくは０．１０質量％以上である。上記割合は、５質量％以下、３質量％以下であってもよく、実質的に含まなくてもよい。 The proportion of the polyfunctional monomer in 100% by mass of the total amount of all monomer components constituting the acrylic polymer is preferably 0.05% by mass or more, more preferably 0.07% by mass, and still more preferably 0.07% by mass. It is 10% by mass or more. The above ratio may be 5% by mass or less, 3% by mass or less, or may be substantially absent.
　上記アクリル系ポリマーは光重合開始剤に由来する構造部を有することが好ましい。上記アクリル系ポリマーが光重合開始剤に由来する構造部を有することは、上記アクリル系ポリマーおよび本発明の粘着剤層が活性エネルギー線照射により重合したポリマーまたは硬化した粘着剤層であることを意味する。上記光重合開始剤としては、後述のものが挙げられる。 The acrylic polymer preferably has a structural portion derived from a photopolymerization initiator. That the acrylic polymer has a structural part derived from a photopolymerization initiator means that the acrylic polymer and the pressure-sensitive adhesive layer of the present invention are a polymer or a cured pressure-sensitive adhesive layer polymerized by irradiation with active energy rays. do. Examples of the photopolymerization initiator include those described below.
　上記アクリル系ポリマーは、アクリル系部分重合物、アクリル系オリゴマー、およびモノマー成分からなる群より選択される１以上を含む組成物を重合して得られる重合反応物であることが好ましい。なお、モノマー成分のみからなる組成物を重合して得られる重合反応物である場合、上記モノマー成分はアクリル系モノマーを少なくとも含む。上記「部分重合物」とは、「プレポリマー」、「シロップ」などと称する場合もある。アクリル系部分重合体、アクリル系オリゴマー、およびモノマー成分は、それぞれ、一種のみを使用してもよいし、二種以上を使用してもよい。なお、上記組成物に含まれ得るモノマー成分を「モノマー成分（Ｃ）」と称する場合がある。 The acrylic polymer is preferably a polymerization reaction product obtained by polymerizing a composition containing one or more selected from the group consisting of acrylic partial polymers, acrylic oligomers, and monomer components. In addition, in the case of a polymerization reaction product obtained by polymerizing a composition consisting only of monomer components, the monomer component contains at least an acrylic monomer. The above-mentioned "partially polymerized product" may also be referred to as "prepolymer", "syrup", and the like. Each of the acrylic partial polymer, the acrylic oligomer, and the monomer component may be used alone or in combination of two or more. In addition, the monomer component that can be contained in the composition may be referred to as "monomer component (C)".
　上記アクリル系ポリマーは、中でも、アクリル系部分重合物を含む組成物の重合反応物であることが好ましく、アクリル系部分重合物およびモノマー成分（Ｃ）を含む組成物の重合反応物であることが特に好ましい。上記アクリル系ポリマーが、アクリル系部分重合物とともにモノマー成分（Ｃ）を含む組成物の重合反応物であると、当該モノマー成分（Ｃ）が本発明の粘着剤層中で低分子量のポリマーを形成することによるものと推測され、初期粘着性に特に優れる両面粘着シートを容易に作製することができる。 Above all, the acrylic polymer is preferably a polymerization reaction product of a composition containing an acrylic partial polymer, and is preferably a polymerization reaction product of a composition containing an acrylic partial polymer and the monomer component (C). Especially preferred. When the acrylic polymer is a polymerization reaction product of a composition containing a monomer component (C) together with an acrylic partial polymer, the monomer component (C) forms a low-molecular-weight polymer in the pressure-sensitive adhesive layer of the present invention. A double-sided pressure-sensitive adhesive sheet having particularly excellent initial pressure-sensitive adhesiveness can be easily produced.
　上記アクリル系部分重合物および上記アクリル系オリゴマーは、いずれもアクリル系モノマーを必須のモノマー成分として構成される化合物である。上記アクリル系部分重合物および上記アクリル系オリゴマーを構成するモノマー成分ならびにモノマー成分（Ｃ）としては、上述のアクリル系ポリマーを構成するモノマー成分として例示および説明されたものが挙げられる。 Both the acrylic partial polymer and the acrylic oligomer are compounds composed of an acrylic monomer as an essential monomer component. Examples of the monomer component and the monomer component (C) constituting the acrylic partial polymer and the acrylic oligomer include those exemplified and explained as the monomer component constituting the acrylic polymer.
　上記アクリル系部分重合物は、完全重合物とは異なり、モノマー成分を、例えば重合転化率９５質量％以下として重合して得られる。上記重合転化率は、好ましくは７０質量％以下、より好ましくは６０質量％以下、さらに好ましくは５０質量％以下、さらに好ましくは４０質量％以下、特に好ましくは３５質量％以下である。上記重合転化率は、好ましくは１質量％以上、より好ましくは５質量％以上である。 Unlike the complete polymer, the acrylic partial polymer is obtained by polymerizing the monomer components at a polymerization conversion rate of 95% by mass or less, for example. The polymerization conversion rate is preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less. The polymerization conversion rate is preferably 1% by mass or more, more preferably 5% by mass or more.
　上記アクリル系部分重合物は、構成単位としてアクリル系モノマーを含む。上記アクリル系部分重合物は、構成単位として（メタ）アクリル酸アルキルエステル（Ａ）を含むことが好ましい。（メタ）アクリル酸アルキルエステル（Ａ）としては、（メタ）アクリル酸ブチルが好ましい。上記構成単位として含まれる（メタ）アクリル酸アルキルエステル（Ａ）は、一種のみであってもよく二種以上であってもよい。 The above acrylic partial polymer contains an acrylic monomer as a structural unit. The acrylic partial polymer preferably contains (A) a (meth)acrylic acid alkyl ester as a structural unit. As the (meth)acrylic acid alkyl ester (A), butyl (meth)acrylate is preferable. The (meth)acrylic acid alkyl ester (A) contained as the structural unit may be of one type or two or more types.
　上記アクリル系部分重合物を構成する全モノマー成分の総量１００質量％中の、（メタ）アクリル酸アルキルエステル（Ａ）の割合は、５０質量％以上であることが好ましく、より好ましくは６０質量％以上、さらに好ましくは６５質量％以上である。上記割合は、９４質量％以下が好ましく、より好ましくは９０質量％以下、さらに好ましくは８５質量％以下である。 The proportion of the (meth)acrylic acid alkyl ester (A) in 100% by mass of the total amount of all monomer components constituting the acrylic partial polymer is preferably 50% by mass or more, more preferably 60% by mass. above, more preferably at least 65% by mass. The proportion is preferably 94% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.
　上記アクリル系部分重合物は、構成単位としてモノマー成分（Ｂ）を含むことが好ましい。上記構成単位として含まれるモノマー成分（Ｂ）は、一種のみであってもよく二種以上であってもよい。 The acrylic partial polymer preferably contains the monomer component (B) as a structural unit. The monomer component (B) contained as the structural unit may be of one type or two or more types.
　上記アクリル系部分重合物を構成する全モノマー成分の総量１００質量％中の、モノマー成分（Ｂ）の割合は、５質量％以上であることが好ましく、より好ましくは１０質量％以上、さらに好ましくは１５質量％以上である。上記割合が５質量％以上であると、貯蔵弾性率Ｇ’（特に、－２０℃における貯蔵弾性率Ｇ’）が高くなり、より耐衝撃性に優れる。モノマー成分（Ｂ）の割合は、６０質量％以下が好ましく、より好ましくは５０質量％以下、さらに好ましくは４０質量％以下である。上記割合が６０質量％以下であると、柔軟性が向上し、被着体に対する密着性やせん断接着力をより向上させることができる。 The proportion of the monomer component (B) in the total amount of 100% by mass of all the monomer components constituting the acrylic partial polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably It is 15% by mass or more. When the above ratio is 5% by mass or more, the storage elastic modulus G' (in particular, the storage elastic modulus G' at -20°C) is high, and the impact resistance is more excellent. The proportion of the monomer component (B) is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. When the above ratio is 60% by mass or less, the flexibility is improved, and the adhesiveness to the adherend and the shear adhesive strength can be further improved.
　上記アクリル系部分重合物は、構成単位として上記共重合性モノマーを含んでいてもよい。上記共重合性モノマーとしては、中でも、凝集力が向上し耐衝撃性により優れる観点、および薄くても良好な密着性を有する粘着剤層を形成可能である観点から、カルボキシ基含有モノマーおよび／または酸無水物モノマーが好ましい。 The acrylic partial polymer may contain the copolymerizable monomer as a structural unit. As the copolymerizable monomer, among others, from the viewpoint of improving cohesive strength and excellent impact resistance, and from the viewpoint of being able to form a pressure-sensitive adhesive layer having good adhesion even if it is thin, a carboxy group-containing monomer and / or Anhydride monomers are preferred.
　上記アクリル系部分重合物を構成する全モノマー成分の総量１００質量％中の、カルボキシ基含有モノマーおよび／または酸無水物モノマーの割合は、特に限定されないが、０．２質量％以上であることが好ましく、より好ましくは１質量％以上、さらに好ましくは５質量％以上である。上記割合は、２０質量％以下が好ましく、より好ましくは１５質量％以下、さらに好ましくは１１質量％以下である。 The ratio of the carboxy group-containing monomer and/or the acid anhydride monomer in the total amount of 100% by mass of all the monomer components constituting the acrylic partial polymer is not particularly limited, but is preferably 0.2% by mass or more. It is preferably 1% by mass or more, and still more preferably 5% by mass or more. The proportion is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 11% by mass or less.
　上記アクリル系ポリマーは、アクリル系部分重合物およびアクリル系オリゴマーを含む組成物の重合反応物であってもよい。この場合、－２０℃における貯蔵弾性率Ｇ’がより向上する。 The above acrylic polymer may be a polymerization reaction product of a composition containing an acrylic partial polymer and an acrylic oligomer. In this case, the storage elastic modulus G' at -20°C is further improved.
　上記アクリル系オリゴマーの重量平均分子量は、２５００～１００００であることが好ましく、より好ましくは３０００～８０００である。なお、上記重量平均分子量は、ＧＰＣ法によりポリスチレン換算して求めることができる。例えば、東ソー株式会社製の高速ＧＰＣ装置「ＨＰＬＣ－８１２０ＧＰＣ」を用いて、下記の条件により測定することができる。
カラム：ＴＳＫｇｅｌ　ＳｕｐｅｒＨＺＭ－Ｈ／ＨＺ４０００／ＨＺ３０００／ＨＺ２０００
溶媒：テトラヒドロフラン
流速：０．６ｍｌ／分 The acrylic oligomer preferably has a weight average molecular weight of 2,500 to 10,000, more preferably 3,000 to 8,000. In addition, the said weight average molecular weight can be calculated|required by polystyrene conversion by GPC method. For example, it can be measured under the following conditions using a high-speed GPC apparatus "HPLC-8120GPC" manufactured by Tosoh Corporation.
Column: TSKgel SuperHZM-H/HZ4000/HZ3000/HZ2000
Solvent: Tetrahydrofuran Flow rate: 0.6 ml/min
　上記アクリル系オリゴマーは、構成単位としてアクリル系モノマーを含む。上記アクリル系オリゴマーは、構成単位としてモノマー成分（Ｂ）を含むことが好ましい。上記構成単位として含まれるモノマー成分は、一種のみであってもよく二種以上であってもよい。 The above acrylic oligomer contains an acrylic monomer as a structural unit. The acrylic oligomer preferably contains a monomer component (B) as a structural unit. The monomer component contained as the structural unit may be of one type or two or more types.
　上記アクリル系オリゴマーを構成する全モノマー成分の総量１００質量％中の、モノマー成分（Ｂ）の割合は、４０質量％以上であることが好ましく、より好ましくは５０質量％以上、さらに好ましくは５５質量％以上である。上記割合は、９０質量％以下が好ましく、より好ましくは８０質量％以下である。 The proportion of the monomer component (B) in the total amount of 100% by mass of all the monomer components constituting the acrylic oligomer is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 55% by mass. % or more. The ratio is preferably 90% by mass or less, more preferably 80% by mass or less.
　上記アクリル系オリゴマーは、構成単位としてメタクリル酸メチル（ＭＭＡ）を含むことが好ましい。上記アクリル系オリゴマーを構成する全モノマー成分中のメタクリル酸メチルの割合は、１０質量％以上であることが好ましく、より好ましくは２０質量％以上である。上記割合は、６０質量％以下が好ましく、より好ましくは５０質量％以下、さらに好ましくは４５質量％以下である。また、上記アクリル系オリゴマーは、構成単位として上記共重合性モノマーを含んでいてもよい。 The above acrylic oligomer preferably contains methyl methacrylate (MMA) as a structural unit. The proportion of methyl methacrylate in all monomer components constituting the acrylic oligomer is preferably 10% by mass or more, more preferably 20% by mass or more. The proportion is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less. Further, the acrylic oligomer may contain the copolymerizable monomer as a structural unit.
　上記アクリル系オリゴマーの含有量は、上記アクリル系部分重合物の総量１００質量部に対して、０．５～３５質量部であることが好ましく、より好ましくは２～２０質量部、さらに好ましくは４～１０質量部である。上記含有量が上記範囲内であると、－２０℃における貯蔵弾性率Ｇ’が高くなる傾向がある。 The content of the acrylic oligomer is preferably 0.5 to 35 parts by mass, more preferably 2 to 20 parts by mass, and still more preferably 4 parts by mass with respect to 100 parts by mass of the acrylic partial polymer. ~10 parts by mass. When the content is within the above range, the storage elastic modulus G' at -20°C tends to increase.
　モノマー成分（Ｃ）としては、上述のアクリル系ポリマーが構成単位として含み得るモノマー成分として例示および説明されたものが挙げられる。モノマー成分（Ｃ）は、モノマー成分（Ｂ）および／または上記アクリル系部分重合物を形成するモノマー成分と共重合可能なモノマーを含むことが好ましい。上記共重合可能なモノマーとしては、上述の共重合性モノマーが挙げられる。 Examples of the monomer component (C) include those exemplified and explained as the monomer components that the acrylic polymer can contain as structural units. The monomer component (C) preferably contains a monomer copolymerizable with the monomer component (B) and/or the monomer component forming the acrylic partial polymer. Examples of the copolymerizable monomer include the copolymerizable monomers described above.
　モノマー成分（Ｃ）がモノマー成分（Ｂ）を含む場合、モノマー成分（Ｃ）中のモノマー成分（Ｂ）の割合は、６０質量％以上が好ましく、より好ましくは７０質量％以上である。 When the monomer component (C) contains the monomer component (B), the proportion of the monomer component (B) in the monomer component (C) is preferably 60% by mass or more, more preferably 70% by mass or more.
　上記アクリル系部分重合物を形成するモノマー成分と共重合可能なモノマーとしては、中でも、薄くても良好な密着性を有する粘着剤層を形成可能である観点から、カルボキシ基含有モノマーおよび／または酸無水物モノマーが好ましい。モノマー成分（Ｃ）が上記共重合可能なモノマーを含む場合、モノマー成分（Ｃ）中の上記共重合可能なモノマーの割合は、特に限定されないが、５質量％以上が好ましく、より好ましくは１０質量％以上である。 As the monomer that can be copolymerized with the monomer component that forms the acrylic partial polymer, among others, from the viewpoint of being able to form a pressure-sensitive adhesive layer that is thin but has good adhesion, a carboxy group-containing monomer and/or an acid Anhydride monomers are preferred. When the monomer component (C) contains the copolymerizable monomer, the ratio of the copolymerizable monomer in the monomer component (C) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass. % or more.
　モノマー成分（Ｃ）がモノマー成分（Ｂ）および上記共重合可能なモノマーを含む場合、モノマー成分（Ｃ）中のモノマー成分（Ｂ）の割合は、６０～９５質量％が好ましく、より好ましくは７０～９０質量％である。また、上記の場合、モノマー成分（Ｃ）中の上記共重合可能なモノマーの割合は、特に限定されないが、５～４０質量％であることが好ましく、より好ましくは１０～３０質量％である。 When the monomer component (C) contains the monomer component (B) and the copolymerizable monomer, the proportion of the monomer component (B) in the monomer component (C) is preferably 60 to 95% by mass, more preferably 70%. ~90% by mass. In the above case, the proportion of the copolymerizable monomer in the monomer component (C) is not particularly limited, but is preferably 5 to 40% by mass, more preferably 10 to 30% by mass.
　モノマー成分（Ｃ）の含有量は、上記アクリル系部分重合物の総量１００質量部に対して、１～３０質量部であることが好ましく、より好ましくは１０～２０質量部である。上記含有量が上記範囲内であると、初期接着力がよりいっそう優れる。また、貯蔵弾性率Ｇ’がより向上し、せん断接着力がより高くなる。 The content of the monomer component (C) is preferably 1 to 30 parts by mass, more preferably 10 to 20 parts by mass, based on 100 parts by mass of the acrylic partial polymer. When the content is within the above range, the initial adhesive strength is even more excellent. In addition, the storage elastic modulus G' is further improved, and the shear adhesive strength is further increased.
　上記アクリル系部分重合物や上記アクリル系オリゴマーは、モノマー成分を重合することにより得られる。また、上記アクリル系ポリマーは、上記アクリル系部分重合物、上記アクリル系オリゴマー、およびモノマー成分（Ｃ）からなる群より選択される１以上を含む組成物を重合することにより得られる。これらの重合方法としては、特に限定されないが、例えば、溶液重合方法、乳化重合方法、塊状重合方法、熱重合方法、活性エネルギー線照射による重合方法（活性エネルギー線重合方法）などが挙げられる。中でも、粘着剤層の透明性、コストなどの点より、塊状重合方法、熱重合方法、活性エネルギー線重合方法が好ましい。 The acrylic partial polymer and the acrylic oligomer are obtained by polymerizing monomer components. The acrylic polymer is obtained by polymerizing a composition containing one or more selected from the group consisting of the acrylic partial polymer, the acrylic oligomer, and the monomer component (C). These polymerization methods are not particularly limited, but include, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a thermal polymerization method, and a polymerization method by active energy ray irradiation (active energy ray polymerization method). Among them, the bulk polymerization method, the thermal polymerization method, and the active energy ray polymerization method are preferable from the viewpoints of the transparency of the pressure-sensitive adhesive layer and the cost.
　また、上記モノマー成分などの重合に際しては、各種の一般的な溶剤が用いられてもよい。上記溶剤としては、例えば、酢酸エチル、酢酸ｎ－ブチル等のエステル類；トルエン、ベンゼン等の芳香族炭化水素類；ｎ－ヘキサン、ｎ－ヘプタン等の脂肪族炭化水素類；シクロヘキサン、メチルシクロヘキサン等の脂環式炭化水素類；メチルエチルケトン、メチルイソブチルケトン等のケトン類などの有機溶剤が挙げられる。なお、溶剤は、一種のみを使用してもよく、二種以上を使用してもよい。 In addition, various general solvents may be used in the polymerization of the above-mentioned monomer components. Examples of the solvent include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane, methylcyclohexane and the like. alicyclic hydrocarbons; and organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. In addition, a solvent may use only 1 type, and may use 2 or more types.
　上記のモノマー成分の重合に際しては、重合反応の種類に応じて、熱重合開始剤や光重合開始剤（光開始剤）などの重合開始剤が用いられてもよい。なお、重合開始剤は、一種のみを使用してもよく、二種以上を使用してもよい。 In the polymerization of the above monomer components, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) may be used depending on the type of polymerization reaction. In addition, a polymerization initiator may use only 1 type, and may use 2 or more types.
　上記熱重合開始剤としては、特に限定されないが、例えば、アゾ系重合開始剤、過酸化物系重合開始剤（例えば、ジベンゾイルペルオキシド、ｔｅｒｔ－ブチルペルマレエート、過硫酸カリウム等の過硫酸塩、ベンゾイルパーオキサイド、過酸化水素等）、フェニル置換エタン等の置換エタン系開始剤、芳香族カルボニル化合物、レドックス系重合開始剤等が挙げられる。中でも、特開２００２－６９４１１号公報に開示されたアゾ系重合開始剤が好ましい。上記アゾ系重合開始剤としては、２，２’－アゾビスイソブチロニトリル、２，２’－アゾビス－２－メチルブチロニトリル、２，２’－アゾビス（２－メチルプロピオン酸）ジメチル、４，４’－アゾビス－４－シアノバレリアン酸などが挙げられる。熱重合開始剤の使用量は、通常の使用量であればよく、例えば、モノマー成分１００質量部に対して例えば０．００５～１質量部、好ましくは０．０１～１質量部の範囲から選択することができる。 The thermal polymerization initiator is not particularly limited. , benzoyl peroxide, hydrogen peroxide, etc.), substituted ethane-based initiators such as phenyl-substituted ethane, aromatic carbonyl compounds, redox-based polymerization initiators, and the like. Among them, the azo polymerization initiator disclosed in JP-A-2002-69411 is preferable. Examples of the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis(2-methylpropionate)dimethyl, 4,4'-azobis-4-cyanovaleric acid and the like. The amount of the thermal polymerization initiator to be used may be a normal amount, for example, 0.005 to 1 part by mass, preferably 0.01 to 1 part by mass based on 100 parts by mass of the monomer component. can do.
　上記光重合開始剤としては、特に限定されないが、例えば、ベンゾインエーテル系光重合開始剤、アセトフェノン系光重合開始剤、α－ケトール系光重合開始剤、芳香族スルホニルクロリド系光重合開始剤、光活性オキシム系光重合開始剤、ベンゾイン系光重合開始剤、ベンジル系光重合開始剤、ベンゾフェノン系光重合開始剤、ケタール系光重合開始剤、チオキサントン系光重合開始剤などが挙げられる。他にも、アシルフォスフィンオキサイド系光重合開始剤、チタノセン系光重合開始剤が挙げられる。上記ベンゾインエーテル系光重合開始剤としては、例えば、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインプロピルエーテル、ベンゾインイソプロピルエーテル、ベンゾインイソブチルエーテル、２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン、アニソールメチルエーテルなどが挙げられる。上記アセトフェノン系光重合開始剤としては、例えば、２，２－ジエトキシアセトフェノン、２，２－ジメトキシ－２－フェニルアセトフェノン、１－ヒドロキシシクロヘキシルフェニルケトン、４－フェノキシジクロロアセトフェノン、４－（ｔ－ブチル）ジクロロアセトフェノンなどが挙げられる。上記α－ケトール系光重合開始剤としては、例えば、２－メチル－２－ヒドロキシプロピオフェノン、１－［４－（２－ヒドロキシエチル）フェニル］－２－メチルプロパン－１－オンなどが挙げられる。上記芳香族スルホニルクロリド系光重合開始剤としては、例えば、２－ナフタレンスルホニルクロライドなどが挙げられる。上記光活性オキシム系光重合開始剤としては、例えば、１－フェニル－１，１－プロパンジオン－２－（Ｏ－エトキシカルボニル）－オキシムなどが挙げられる。上記ベンゾイン系光重合開始剤としては、例えば、ベンゾインなどが挙げられる。上記ベンジル系光重合開始剤としては、例えば、ベンジルなどが挙げられる。上記ベンゾフェノン系光重合開始剤としては、例えば、ベンゾフェノン、ベンゾイル安息香酸、３，３’－ジメチル－４－メトキシベンゾフェノン、ポリビニルベンゾフェノン、α－ヒドロキシシクロヘキシルフェニルケトンなどが挙げられる。上記ケタール系光重合開始剤としては、例えば、ベンジルジメチルケタールなどが挙げられる。上記チオキサントン系光重合開始剤としては、例えば、チオキサントン、２－クロロチオキサントン、２－メチルチオキサントン、２，４－ジメチルチオキサントン、イソプロピルチオキサントン、２，４－ジイソプロピルチオキサントン、ドデシルチオキサントンなどが挙げられる。上記アシルフォスフィンオキサイド系光重合開始剤としては、例えば、２，４，６－トリメチルベンゾイル－ジフェニル－フォスフィンオキサイド、ビス（２，４，６－トリメチルベンゾイル）－フェニルフォスフィンオキサイドなどが挙げられる。上記チタノセン系光重合開始剤としては、例えば、ビス（η5－２，４－シクロペンタジエン－１－イル）－ビス（２，６－ジフルオロ－３－（１Ｈ－ピロール－１－イル）－フェニル）チタニウムなどが挙げられる。光重合開始剤の使用量は、通常の使用量であればよく、例えば、モノマー成分１００質量部に対して例えば０．０１～３質量部、好ましくは０．１～１．５質量部の範囲から選択することができる。 The photopolymerization initiator is not particularly limited. Examples include active oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators. Other examples include acylphosphine oxide photopolymerization initiators and titanocene photopolymerization initiators. Examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one, anisole methyl ether and the like. Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, 4-phenoxydichloroacetophenone, 4-(t-butyl ) and dichloroacetophenone. Examples of the α-ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. be done. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)-oxime. Examples of the benzoin-based photopolymerization initiator include benzoin. Examples of the benzyl-based photopolymerization initiator include benzyl. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone, and the like. Examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone. Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. . Examples of the titanocene-based photopolymerization initiator include bis(η 5 -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl ) and titanium. The amount of the photopolymerization initiator used may be a normal amount, for example, 0.01 to 3 parts by mass, preferably 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the monomer component. You can choose from
　本発明の粘着剤層は、さらに、フィラーを含有することが好ましい。フィラーを配合することで、－２０℃および６５℃における貯蔵弾性率Ｇ’を調整することが容易となる。上記フィラーは、一種のみを使用してもよいし、二種以上を使用してもよい。 The adhesive layer of the present invention preferably further contains a filler. By blending the filler, it becomes easy to adjust the storage elastic modulus G' at -20°C and 65°C. Only one type of the filler may be used, or two or more types may be used.
　上記フィラーの形状は、特に限定されず、粒子状や繊維状のフィラーを用いることができる。中でも、粒子状が好ましい。上記フィラーとしては、有機物、無機物のいずれであってもよい。 The shape of the filler is not particularly limited, and a particulate or fibrous filler can be used. Among them, a particulate form is preferable. The filler may be either an organic substance or an inorganic substance.
　上記無機物を構成する材料としては、例えば、銅、銀、金、白金、ニッケル、アルミニウム、クロム、鉄、ステンレス等の金属；酸化アルミニウム、酸化ケイ素（二酸化ケイ素）、酸化チタン、酸化ジルコニウム、酸化亜鉛、酸化スズ、酸化銅、酸化ニッケル等の金属酸化物；水酸化アルミニウム、ベーマイト、水酸化マグネシウム、水酸化カルシウム、水酸化亜鉛、珪酸、水酸化鉄、水酸化銅、水酸化バリウム、酸化ジルコニウム水和物、酸化スズ水和物、塩基性炭酸マグネシウム、ハイドロタルサイト、ドウソナイト、硼砂、ホウ酸亜鉛等の金属水酸化物および水和金属化合物；炭化ケイ素、炭化ホウ素、炭化窒素、炭化カルシウム等の炭化物；窒化アルミニウム、窒化ケイ素、窒化ホウ素、窒化ガリウム等の窒化物；炭酸カルシウム等の炭酸塩；チタン酸バリウム、チタン酸カリウム等のチタン酸塩；カーボンブラック、カーボンチューブ（カーボンナノチューブ）、カーボンファイバー、ダイヤモンド等の炭素系物質；ガラス等の無機材料；火山シラス、クレー、砂等の天然原料粒子などが挙げられる。 Examples of materials constituting the above inorganic substances include metals such as copper, silver, gold, platinum, nickel, aluminum, chromium, iron, and stainless steel; aluminum oxide, silicon oxide (silicon dioxide), titanium oxide, zirconium oxide, and zinc oxide. , tin oxide, copper oxide, nickel oxide and other metal oxides; aluminum hydroxide, boehmite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, silicic acid, iron hydroxide, copper hydroxide, barium hydroxide, zirconium oxide water hydrates, tin oxide hydrates, basic magnesium carbonate, hydrotalcite, dawsonite, borax, zinc borate and other metal hydroxides and hydrated metal compounds; silicon carbide, boron carbide, nitrogen carbide, calcium carbide, etc. Carbide; nitrides such as aluminum nitride, silicon nitride, boron nitride, gallium nitride; carbonates such as calcium carbonate; titanates such as barium titanate and potassium titanate; carbon black, carbon tube (carbon nanotube), carbon fiber , carbonaceous materials such as diamond; inorganic materials such as glass; natural raw material particles such as volcanic shirasu, clay, sand, and the like.
　上記有機物を構成する材料としては、例えば、ポリスチレン、アクリル樹脂（例えばポリメチルメタクリレート）、フェノール樹脂、ベンゾグアナミン樹脂、尿素樹脂、シリコーン樹脂、ポリエステル、ポリウレタン、ポリエチレン、ポリプロピレン、ポリアミド（例えばナイロン等）、ポリイミド、ポリ塩化ビニリデン等のポリマーなどが挙げられる。 Examples of materials constituting the above organic matter include polystyrene, acrylic resin (e.g., polymethyl methacrylate), phenol resin, benzoguanamine resin, urea resin, silicone resin, polyester, polyurethane, polyethylene, polypropylene, polyamide (e.g., nylon), and polyimide. , and polymers such as polyvinylidene chloride.
　上記フィラーは、中空体構造を有するものであってもよい。上記中空体構造を有するフィラーの中空部（中空粒子の内部の空間）は、真空状態であってもよいし、媒質で満たされていてもよい。上記媒質としては、例えば、窒素、アルゴン等の不活性ガスや空気、揮発性溶剤などが挙げられる。 The filler may have a hollow body structure. The hollow portion (internal space of the hollow particles) of the filler having the hollow body structure may be in a vacuum state or may be filled with a medium. Examples of the medium include inert gases such as nitrogen and argon, air, and volatile solvents.
　上記フィラーとしては、中でも、表面がアクリル系樹脂以外の有機物または無機物で構成されるフィラー、中空体構造を有するフィラーが好ましい。これらのフィラーは、アクリル系粘着剤層中のアクリル成分との相互作用が小さく、または中空体構造を有するため、粘着剤層が延びた際に破断しにくく、両面粘着シートを被着体に貼付した後に剥離する際の剥離性（リワーク性）に優れる。 As the filler, among others, a filler whose surface is composed of an organic or inorganic substance other than an acrylic resin and a filler having a hollow body structure are preferable. These fillers have little interaction with the acrylic component in the acrylic pressure-sensitive adhesive layer or have a hollow body structure, so when the pressure-sensitive adhesive layer is stretched, it is difficult to break, and the double-sided pressure-sensitive adhesive sheet can be attached to the adherend. Excellent peelability (reworkability) when peeling off after bonding.
　上記粒子状のフィラーの平均粒径は、例えば０．５～８０μｍであり、好ましくは１～４０μｍである。上記平均粒径が上記範囲内であると、粘着剤層の硬さを適度なものとすることができる。なお、上記平均粒径は、動的光散乱法により測定されるメディアン径（Ｄ５０）である。 The average particle size of the particulate filler is, for example, 0.5 to 80 μm, preferably 1 to 40 μm. When the average particle diameter is within the above range, the pressure-sensitive adhesive layer can have an appropriate hardness. In addition, the said average particle diameter is a median diameter (D50) measured by a dynamic light-scattering method.
　本発明の粘着剤層中の上記フィラーの割合は、上記粘着剤層の総量１００質量％に対して、０．５～１０質量％が好ましく、より好ましくは１～５質量％である。上記割合が上記範囲内であると、粘着剤層の硬さを適度なものとすることができる。また、リワーク性に優れる。 The proportion of the filler in the adhesive layer of the present invention is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, relative to 100% by mass of the total amount of the adhesive layer. When the above ratio is within the above range, the hardness of the pressure-sensitive adhesive layer can be made appropriate. Moreover, it is excellent in reworkability.
　本発明の粘着剤層は、着色剤を含有していてもよい。着色剤を含むことで粘着剤層は着色し、本発明の両面粘着シートは視認性および意匠性に優れる。上記着色剤は、顔料であってもよいし、染料であってもよい。着色剤としては、例えば、黒系着色剤、シアン系着色剤、マゼンダ系着色剤、イエロー系着色剤等が挙げられる。視認性および意匠性により優れる観点からは、黒系着色剤が好ましい。上記着色剤は、一種のみを含有していてもよいし、二種以上を含有していてもよい。本発明の粘着剤層中の上記着色剤の割合は、上記粘着剤層の総量１００質量％に対して、０．０５～５質量％が好ましく、より好ましくは０．１～２質量％である。 The adhesive layer of the present invention may contain a coloring agent. The pressure-sensitive adhesive layer is colored by containing a coloring agent, and the double-sided pressure-sensitive adhesive sheet of the present invention is excellent in visibility and design. The coloring agent may be a pigment or a dye. Examples of coloring agents include black coloring agents, cyan coloring agents, magenta coloring agents, and yellow coloring agents. A black colorant is preferable from the viewpoint of better visibility and design. The coloring agent may contain only one kind, or may contain two or more kinds. The proportion of the coloring agent in the pressure-sensitive adhesive layer of the present invention is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, with respect to 100% by mass of the total amount of the pressure-sensitive adhesive layer. .
　黒系着色剤としては、例えば、カーボンブラック、カーボンナノチューブ、グラファイト（黒鉛）、酸化銅、二酸化マンガン、アゾメチンアゾブラック等のアゾ系顔料、アニリンブラック、ペリレンブラック、チタンブラック、シアニンブラック、活性炭、フェライト、マグネタイト、酸化クロム、酸化鉄、二硫化モリブデン、複合酸化物系黒色色素、アントラキノン系有機黒色染料、アゾ系有機黒色染料等が挙げられる。カーボンブラックとしては、例えば、ファーネスブラック、チャンネルブラック、アセチレンブラック、サーマルブラック、ランプブラックなどが挙げられる。黒系着色剤としては、Ｃ．Ｉ．ソルベントブラック３、同７、同２２、同２７、同２９、同３４、同４３、同７０；Ｃ．Ｉ．ダイレクトブラック１７、同１９、同２２、同３２、同３８、同５１、同７１；Ｃ．Ｉ．アシッドブラック１、同２、同２４、同２６、同３１、同４８、同５２、同１０７、同１０９、同１１０、同１１９、同１５４；Ｃ．Ｉ．ディスパーズブラック１、同３、同１０、同２４；Ｃ．Ｉ．ピグメントブラック１、同７なども挙げられる。 Examples of black colorants include carbon black, carbon nanotubes, graphite (graphite), copper oxide, manganese dioxide, azo pigments such as azomethine azo black, aniline black, perylene black, titanium black, cyanine black, activated carbon, and ferrite. , magnetite, chromium oxide, iron oxide, molybdenum disulfide, complex oxide-based black dyes, anthraquinone-based organic black dyes, and azo-based organic black dyes. Examples of carbon black include furnace black, channel black, acetylene black, thermal black and lamp black. As a black colorant, C.I. I. Solvent Black 3, 7, 22, 27, 29, 34, 43, 70; C.I. I. Direct Black 17, 19, 22, 32, 38, 51, 71; C.I. I. Acid Black 1, 2, 24, 26, 31, 48, 52, 107, 109, 110, 119, 154; C.I. I. Disperse Black 1, 3, 10, 24; C.I. I. Pigment Black 1 and Pigment Black 7 are also included.
　シアン系着色剤としては、例えば、Ｃ．Ｉ．ソルベントブルー２５、同３６、同６０、同７０、同９３、同９５；Ｃ．Ｉ．アシッドブルー６、同４５；Ｃ．Ｉ．ピグメントブルー１、同２、同３、同１５、同１５：１、同１５：２、同１５：３、同１５：４、同１５：５、同１５：６、同１６、同１７、同１７：１、同１８、同２２、同２５、同５６、同６０、同６３、同６５、同６６；Ｃ．Ｉ．バットブルー４；同６０、Ｃ．Ｉ．ピグメントグリーン７などが挙げられる。 As a cyan colorant, for example, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95; C.I. I. Acid Blue 6, 45; C.I. I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17, 17:1, 18, 22, 25, 56, 60, 63, 65, 66; C.I. I. Bat Blue 4; 60, C.I. I. Pigment Green 7 and the like.
　マゼンダ系着色剤としては、例えば、Ｃ．Ｉ．ソルベントレッド１、同３、同８、同２３、同２４、同２５、同２７、同３０、同４９、同５２、同５８、同６３、同８１、同８２、同８３、同８４、同１００、同１０９、同１１１、同１２１、同１２２；Ｃ．Ｉ．ディスパースレッド９；Ｃ．Ｉ．ソルベントバイオレット８、同１３、同１４、同２１、同２７；Ｃ．Ｉ．ディスパースバイオレット１；Ｃ．Ｉ．ベーシックレッド１、同２、同９、同１２、同１３、同１４、同１５、同１７、同１８、同２２、同２３、同２４、同２７、同２９、同３２、同３４、同３５、同３６、同３７、同３８、同３９、同４０；Ｃ．Ｉ．ベーシックバイオレット１、同３、同７、同１０、同１４、同１５、同２１、同２５、同２６、同２７、２８などが挙げられる。また、マゼンダ系着色剤としては、例えば、Ｃ．Ｉ．ピグメントレッド１、同２、同３、同４、同５、同６、同７、同８、同９、同１０、同１１、同１２、同１３、同１４、同１５、同１６、同１７、同１８、同１９、同２１、同２２、同２３、同３０、同３１、同３２、同３７、同３８、同３９、同４０、同４１、同４２、同４８：１、同４８：２、同４８：３、同４８：４、同４９、同４９：１、同５０、同５１、同５２、同５２：２、同５３：１、同５４、同５５、同５６、同５７：１、同５８、同６０、同６０：１、同６３、同６３：１、同６３：２、同６４、同６４：１、同６７、同６８、同８１、同８３、同８７、同８８、同８９、同９０、同９２、同１０１、同１０４、同１０５、同１０６、同１０８、同１１２、同１１４、同１２２、同１２３、同１３９、同１４４、同１４６、同１４７、同１４９、同１５０、同１５１、同１６３、同１６６、同１６８、同１７０、同１７１、同１７２、同１７５、同１７６、同１７７、同１７８、同１７９、同１８４、同１８５、同１８７、同１９０、同１９３、同２０２、同２０６、同２０７、同２０９、同２１９、同２２２、同２２４、同２３８、同２４５；Ｃ．Ｉ．ピグメントバイオレット３、同９、同１９、同２３、同３１、同３２、同３３、同３６、同３８、同４３、同５０；Ｃ．Ｉ．バットレッド１、同２、同１０、同１３、同１５、同２３、同２９、同３５などが挙げられる。 As a magenta colorant, for example, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122; C.I. I. disperse thread 9;C. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Disperse Violet 1; C.I. I. Basic red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28 and the like. Examples of magenta colorants include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 42, 48: 1, 48:2, 48:3, 48:4, 49, 49:1, 50, 51, 52, 52:2, 53:1, 54, 55, 56, 57:1, 58, 60, 60:1, 63, 63:1, 63:2, 64, 64:1, 67, 68, 81, 83, 87, 88, 89, 90, 92, 101, 104, 105, 106, 108, 112, 114, 122, 123, 139, 144, 146, 147, 149, 150, 151, 163, 166, 168, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185 , 187, 190, 193, 202, 206, 207, 209, 219, 222, 224, 238, 245; I. Pigment Violet 3, 9, 19, 23, 31, 32, 33, 36, 38, 43, 50; C.I. I. Batred 1, 2, 10, 13, 15, 23, 29, 35 and the like.
　イエロー系着色剤としては、例えば、Ｃ．Ｉ．ソルベントイエロー１９、同４４、同７７、同７９、同８１、同８２、同９３、同９８、同１０３、同１０４、同１１２、同１６２；Ｃ．Ｉ．ピグメントオレンジ３１、同４３；Ｃ．Ｉ．ピグメントイエロー１、同２、同３、同４、同５、同６、同７、同１０、同１１、同１２、同１３、同１４、同１５、同１６、同１７、同２３、同２４、同３４、同３５、同３７、同４２、同５３、同５５、同６５、同７３、同７４、同７５、同８１、同８３、同９３、同９４、同９５、同９７、同９８、同１００、同１０１、同１０４、同１０８、同１０９、同１１０、同１１３、同１１４、同１１６、同１１７、同１２０、同１２８、同１２９、同１３３、同１３８、同１３９、同１４７、同１５０、同１５１、同１５３、同１５４、同１５５、同１５６、同１６７、同１７２、同１７３、同１８０、同１８５、同１９５；Ｃ．Ｉ．バットイエロー１、同３、同２０などが挙げられる。 Examples of yellow colorants include C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162; I. Pigment Orange 31, 43; C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 113, 114, 116, 117, 120, 128, 129, 133, 138, 139 , 147, 150, 151, 153, 154, 155, 156, 167, 172, 173, 180, 185, 195; I. Bat Yellow 1, 3, 20 and the like.
　本発明の粘着剤層は、必要に応じて、さらに、架橋剤、架橋促進剤、老化防止剤、酸化防止剤、可塑剤、軟化剤、界面活性剤、帯電防止剤、表面潤滑剤、レベリング剤、光安定剤、紫外線吸収剤、重合禁止剤、箔状物、防錆剤などの添加剤を、本発明の効果を損なわない範囲で含有していてもよい。上記添加剤は、それぞれ、一種のみを使用してもよいし、二種以上を使用してもよい。 The pressure-sensitive adhesive layer of the present invention may optionally further contain a cross-linking agent, a cross-linking accelerator, an anti-aging agent, an antioxidant, a plasticizer, a softening agent, a surfactant, an antistatic agent, a surface lubricant, and a leveling agent. , a light stabilizer, an ultraviolet absorber, a polymerization inhibitor, a foil-like material, and an antirust agent may be contained within a range that does not impair the effects of the present invention. Only one kind of the above additives may be used, or two or more kinds thereof may be used.
　本発明の粘着剤層は、上述のように、－２０℃における貯蔵弾性率Ｇ’が１０ＭＰａ以上であり、好ましくは５０ＭＰａ以上、より好ましくは１００ＭＰａ以上、さらに好ましくは２００ＭＰａ以上、特に好ましくは３００ＭＰａ以上である。－２０℃における貯蔵弾性率Ｇ’は、低温における粘着剤層の性質であり、比較的高速で衝撃を受けた場合の性質に置き換えることができる。そのような－２０℃もの低温における貯蔵弾性率Ｇ’が１０ＭＰａ以上であることにより、例えば両面粘着シートが適用された部材が高速落下した際などの耐衝撃性に優れる。上記貯蔵弾性率Ｇ’は、動的粘弾性測定（ＤＭＡ）装置を用いて算出することができる。 As described above, the pressure-sensitive adhesive layer of the present invention has a storage modulus G′ at −20° C. of 10 MPa or more, preferably 50 MPa or more, more preferably 100 MPa or more, still more preferably 200 MPa or more, and particularly preferably 300 MPa or more. is. The storage elastic modulus G' at -20°C is the property of the pressure-sensitive adhesive layer at low temperatures, and can be replaced with the property when impacted at a relatively high speed. When the storage elastic modulus G' at such a low temperature of -20°C is 10 MPa or more, for example, the member to which the double-sided pressure-sensitive adhesive sheet is applied is excellent in impact resistance when dropped at high speed. The storage modulus G' can be calculated using a dynamic viscoelasticity measurement (DMA) device.
　本発明の粘着剤層は、上述のように、６５℃における貯蔵弾性率Ｇ’が０．０５ＭＰａ以上であり、好ましくは０．０６ＭＰａ以上、より好ましくは０．０８ＭＰａ以上、さらに好ましくは０．１０ＭＰａ以上である。６５℃における貯蔵弾性率Ｇ’は、比較的高温における粘着剤層の性質であり、低速衝撃を受けた場合の性質に置き換えることができる。そのような６５℃における貯蔵弾性率Ｇ’が０．０５ＭＰａ以上であることにより、本発明の粘着剤層は高いせん断接着力を有する。上記貯蔵弾性率Ｇ’は、動的粘弾性測定（ＤＭＡ）装置を用いて算出することができる。 As described above, the pressure-sensitive adhesive layer of the present invention has a storage modulus G′ at 65° C. of 0.05 MPa or more, preferably 0.06 MPa or more, more preferably 0.08 MPa or more, and still more preferably 0.10 MPa. That's it. The storage elastic modulus G' at 65°C is the property of the pressure-sensitive adhesive layer at relatively high temperatures, and can be replaced with the property when subjected to low speed impact. Since the storage elastic modulus G' at 65°C is 0.05 MPa or more, the pressure-sensitive adhesive layer of the present invention has high shear adhesive strength. The storage modulus G' can be calculated using a dynamic viscoelasticity measurement (DMA) device.
　本発明の粘着剤層は、２３℃における貯蔵弾性率Ｇ’が０．１０ＭＰａ以上であることが好ましく、より好ましくは０．２１ＭＰａ以上、さらに好ましくは０．２５ＭＰａ以上である。２３℃における貯蔵弾性率Ｇ’が０．１０ＭＰａ以上であると、常温において適度な硬さを有し、リワーク性に優れる。上記貯蔵弾性率Ｇ’は、動的粘弾性測定（ＤＭＡ）装置を用いて算出することができる。 The adhesive layer of the present invention preferably has a storage modulus G' at 23°C of 0.10 MPa or more, more preferably 0.21 MPa or more, and still more preferably 0.25 MPa or more. When the storage elastic modulus G′ at 23° C. is 0.10 MPa or more, it has appropriate hardness at room temperature and excellent reworkability. The storage modulus G' can be calculated using a dynamic viscoelasticity measurement (DMA) device.
　本発明の粘着剤層のガラス転移温度（Ｔｇ）は、０℃以上であり、好ましくは２℃以上、さらに好ましくは５℃以上である。上記Ｔｇが０℃以上であることにより、貯蔵弾性率Ｇ’が高くなり、耐衝撃性に優れる。上記Ｔｇは、例えば５０℃以下である。上記Ｔｇは、動的粘弾性測定（ＤＭＡ）装置を用いて算出することができる。 The glass transition temperature (Tg) of the adhesive layer of the present invention is 0°C or higher, preferably 2°C or higher, and more preferably 5°C or higher. When the Tg is 0° C. or higher, the storage elastic modulus G′ is high and the impact resistance is excellent. The above Tg is, for example, 50° C. or lower. The Tg can be calculated using a dynamic viscoelasticity measurement (DMA) device.
　本発明の粘着剤層のｔａｎδのピークトップ値は、０．５以上であることが好ましく、より好ましくは１．０以上、さらに好ましくは１．５以上である。上記ｔａｎδのピークトップ値が０．５以上であると、より耐衝撃性に優れる。上記ｔａｎδは、動的粘弾性測定（ＤＭＡ）装置を用いて算出することができる。 The peak top value of tan δ of the pressure-sensitive adhesive layer of the present invention is preferably 0.5 or more, more preferably 1.0 or more, and still more preferably 1.5 or more. When the peak top value of tan δ is 0.5 or more, the impact resistance is more excellent. The above tan δ can be calculated using a dynamic viscoelasticity measurement (DMA) device.
　本発明の粘着剤層は活性エネルギー線硬化型粘着剤層である。すなわち、本発明の粘着剤層は、活性エネルギー線硬化性の粘着剤組成物により形成された粘着剤層である。これにより、本発明の両面粘着シートは、架橋が密となって強度の高い粘着剤を作製でき、耐衝撃性に優れ、せん断接着力が高くなる。 The adhesive layer of the present invention is an active energy ray-curable adhesive layer. That is, the pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive layer formed from an active energy ray-curable pressure-sensitive adhesive composition. As a result, the double-sided pressure-sensitive adhesive sheet of the present invention has dense cross-linking and can produce a high-strength pressure-sensitive adhesive, which has excellent impact resistance and high shear adhesive strength.
　上記活性エネルギー線としては、例えば、α線、β線、γ線、中性子線、電子線などの電離性放射線や、紫外線などが挙げられ、特に、紫外線が好ましい。すなわち、上記活性エネルギー線硬化型粘着剤層は紫外線硬化型粘着剤層が好ましい。 Examples of the active energy rays include ionizing radiation such as α-rays, β-rays, γ-rays, neutron beams and electron beams, and ultraviolet rays, with ultraviolet rays being particularly preferred. That is, the active energy ray-curable pressure-sensitive adhesive layer is preferably an ultraviolet-curable pressure-sensitive adhesive layer.
　本発明の粘着剤層は、例えば、上記粘着剤組成物をはく離ライナー上に塗布（塗工）し、必要に応じて加熱等により溶媒を揮発させて乾燥固化し、得られた粘着剤組成物層に活性エネルギー線を照射して硬化させて製造することができる。また、必要に応じて、さらに、加熱乾燥してもよい。 The pressure-sensitive adhesive layer of the present invention can be produced, for example, by applying (coating) the above-described pressure-sensitive adhesive composition onto a release liner and, if necessary, drying and solidifying the solvent by heating to volatilize the pressure-sensitive adhesive composition. It can be produced by irradiating the layer with an active energy ray to cure it. Moreover, you may heat-dry further as needed.
　本発明の粘着剤層を形成する粘着剤組成物（アクリル系粘着剤組成物）としては、例えば、上記アクリル系部分重合物、上記アクリル系オリゴマー、またはモノマー成分（Ｃ）を含むモノマー混合物を必須成分とするアクリル系粘着剤組成物などが挙げられる。 As the adhesive composition (acrylic adhesive composition) forming the adhesive layer of the present invention, for example, the acrylic partial polymer, the acrylic oligomer, or a monomer mixture containing the monomer component (C) is essential. The acrylic adhesive composition used as a component etc. are mentioned.
　上記粘着剤組成物は、初期粘着性により優れる観点から、（メタ）アクリル酸アルキルエステル（Ａ）およびモノマー成分（Ｂ）を含むモノマー混合物の部分重合物と、モノマー成分（Ｃ）と、多官能性モノマーと、光重合開始剤とを少なくとも含むことが好ましい。その他、アクリル系オリゴマーや、フィラー、着色剤などを含んでいてもよい。 From the viewpoint of excellent initial adhesiveness, the pressure-sensitive adhesive composition includes a partial polymer of a monomer mixture containing (meth)acrylic acid alkyl ester (A) and monomer component (B), monomer component (C), and polyfunctional It preferably contains at least a polar monomer and a photopolymerization initiator. In addition, it may contain acrylic oligomers, fillers, colorants, and the like.
（両面粘着シート）
　本発明の両面粘着シートは、本発明の粘着剤層から構成される。上記両面粘着シートの厚さは、５０～５００μｍであることが好ましく、より好ましくは１００～３００μｍである。上記厚さが５０μｍ以上であると、被着体に対する粘着性および追従性に優れる。上記厚さが５００μｍ以下であると、両面粘着シートの厚さをより薄くすることができる。なお、上記両面粘着シートの厚さは、一方の粘着面から他方の粘着面までの厚さ、すなわち粘着体の厚さをいい、はく離ライナーを含まない。 (Double-sided adhesive sheet)
The double-sided pressure-sensitive adhesive sheet of the invention is composed of the pressure-sensitive adhesive layer of the invention. The thickness of the double-sided pressure-sensitive adhesive sheet is preferably 50-500 μm, more preferably 100-300 μm. When the thickness is 50 µm or more, the adhesiveness and conformability to the adherend are excellent. When the thickness is 500 µm or less, the thickness of the double-sided pressure-sensitive adhesive sheet can be made thinner. The thickness of the double-sided pressure-sensitive adhesive sheet refers to the thickness from one pressure-sensitive adhesive surface to the other pressure-sensitive adhesive surface, that is, the thickness of the pressure-sensitive adhesive body, and does not include the release liner.
　本発明の両面粘着シートは、一方の粘着面に厚さ５０μｍのポリエチレンテレフタレート（ＰＥＴ）フィルムを貼り付けた状態での２３℃で測定されるステンレス鋼板に対する１８０°剥離強度は２０Ｎ／２０ｍｍ以上であり、好ましくは２５Ｎ／２０ｍｍ以上、より好ましくは３０Ｎ／２０ｍｍ以上である。上記剥離強度が２０Ｎ／２０ｍｍ以上であることにより、初期粘着性に優れ、例えば電気電子機器における部材同士の貼り合わせに用いた際、部材同士を充分に固定することができる。上記剥離強度は、例えば５０Ｎ／２０ｍｍ以下である。なお、本発明の両面粘着シートについて少なくとも一方の粘着面における１８０°剥離強度が上記範囲内であることが好ましく、両面の粘着面における１８０°剥離強度が上記範囲内であることがより好ましい。なお、本発明の両面粘着シートにはく離ライナーが貼り合わせられている場合、上記剥離強度ははく離ライナーを剥離した状態で測定される値であり、詳細の方法は実施例で示すとおりである。 The double-sided pressure-sensitive adhesive sheet of the present invention has a 180° peel strength against a stainless steel plate measured at 23°C in a state where a polyethylene terephthalate (PET) film having a thickness of 50 µm is attached to one adhesive surface, and the peel strength is 20 N/20 mm or more. , preferably 25 N/20 mm or more, more preferably 30 N/20 mm or more. When the peel strength is 20 N/20 mm or more, the initial tackiness is excellent and, for example, when used to bond members together in electrical and electronic equipment, the members can be sufficiently fixed to each other. The peel strength is, for example, 50 N/20 mm or less. For the double-sided PSA sheet of the present invention, the 180° peel strength on at least one adhesive surface is preferably within the above range, and more preferably the 180° peel strength on both adhesive surfaces is within the above range. When a release liner is attached to the double-sided pressure-sensitive adhesive sheet of the present invention, the above peel strength is a value measured with the release liner removed, and the detailed method is as shown in Examples.
　本発明の両面粘着シートは、２枚のステンレス鋼板で挟むようにして両方の粘着面を貼り合わせ、引張速度１０ｍｍ／分、剥離角度０°の条件で測定した際の、一方のステンレス鋼板に対するせん断接着力が、１．０ＭＰａ以上であることが好ましく、より好ましくは１．３ＭＰａ以上、より好ましくは１．５ＭＰａ以上である。上記せん断接着力が１．０ＭＰａ以上であると、被着体に貼り合わせる際の粘着性に優れる。上記せん断接着力は、リワーク性に優れる観点から、１０ＭＰａ以下が好ましく、より好ましくは５．０ＭＰａ以下、さらに好ましくは３．０ＭＰａ以下である。なお、本発明の両面粘着シートにはく離ライナーが貼り合わせられている場合、上記剥離強度ははく離ライナーを剥離した状態で測定される値であり、詳細の方法は実施例で示すとおりである。 The double-sided pressure-sensitive adhesive sheet of the present invention is sandwiched between two stainless steel plates, and both adhesive surfaces are bonded together, and the shear adhesive strength to one of the stainless steel plates is measured under the conditions of a tensile speed of 10 mm/min and a peeling angle of 0°. is preferably 1.0 MPa or more, more preferably 1.3 MPa or more, and more preferably 1.5 MPa or more. When the shear adhesive strength is 1.0 MPa or more, the adhesiveness when attached to an adherend is excellent. From the viewpoint of excellent reworkability, the shear adhesive strength is preferably 10 MPa or less, more preferably 5.0 MPa or less, and even more preferably 3.0 MPa or less. When a release liner is attached to the double-sided pressure-sensitive adhesive sheet of the present invention, the above peel strength is a value measured with the release liner removed, and the detailed method is as shown in Examples.
　本発明の両面粘着シートの、下記のデュポン式衝撃試験により測定される、いずれか一方のステンレスプレートが剥がれる前までのエネルギー（荷重×高さ）は、０．３以上であることが好ましく、より好ましくは０．４以上である。
＜耐衝撃試験＞
　外径２４．５ｍｍ角、幅２ｍｍの枠状の両面粘着シートを、厚さ２ｍｍ、外形５０ｍｍ角の正方形の中央部に穴の開いたステンレスプレートと、厚さ３ｍｍ、外形２５ｍｍ角の正方形のステンレスプレートの間に挟み込んで圧着し、温度５０℃の環境下に２時間静置し、その後常温に戻して評価サンプルとする。デュポン式衝撃試験機を用い、上記評価サンプルに、落下おもり重量と落下高さを、１００ｇにて５０～５００ｍｍまで５０ｍｍずつ変化、１５０ｇにて３５０～５００ｍｍまで５０ｍｍずつ変化、２００ｇにて４００～５００ｍｍまで５０ｍｍずつ変化、３００ｇにて３５０～５００ｍｍまで５０ｍｍずつ変化させ、剥がれが生じるまでエネルギーが増えていくようにする。この際に、評価済みであるエネルギーについては、試験を行わず、エネルギー量が重複しないように荷重と高さを設定する。その後、少なくともいずれか一方のステンレスプレートが剥がれる前までのエネルギーを荷重×高さで算出する。 The double-sided pressure-sensitive adhesive sheet of the present invention preferably has an energy (load x height) of 0.3 or more before one of the stainless steel plates is peeled off, as measured by the following DuPont impact test. Preferably it is 0.4 or more.
<Shock resistance test>
A frame-shaped double-sided adhesive sheet with an outer diameter of 24.5 mm square and a width of 2 mm was placed on a stainless steel plate with a hole in the center of a square with an outer diameter of 2 mm and an outer diameter of 50 mm, and a stainless steel plate with a square with an outer diameter of 3 mm and an outer diameter of 25 mm. It is sandwiched between plates and pressed, left to stand in an environment at a temperature of 50° C. for 2 hours, and then returned to room temperature to obtain an evaluation sample. Using a DuPont impact tester, the weight and height of the drop weight on the above evaluation sample were changed by 50 mm from 50 to 500 mm at 100 g, changed by 50 mm from 350 to 500 mm at 150 g, and 400 to 500 mm at 200 g. At 300 g, the energy is changed by 50 mm from 350 to 500 mm, and the energy is increased until peeling occurs. At this time, the energy that has already been evaluated is not tested, and the load and height are set so that the amount of energy does not overlap. After that, the energy until at least one of the stainless steel plates peels off is calculated by multiplying the load by the height.
　上記両面粘着シートは、使用時まで、粘着剤層の表面（粘着面）にはく離ライナーが貼り合わせられていてもよい。なお、上記両面粘着シートにおける両面の各粘着面は、２枚のはく離ライナーによりそれぞれ保護されていてもよいし、両面が剥離面となっているはく離ライナー１枚により、ロール状に巻回される形態（巻回体）で保護されていてもよい。はく離ライナーは粘着剤層の保護材として用いられ、被着体に貼付する際に剥がされる。なお、はく離ライナーは必ずしも設けられなくてもよい。 The double-sided pressure-sensitive adhesive sheet may have a release liner attached to the surface (adhesive surface) of the pressure-sensitive adhesive layer until use. The adhesive surfaces on both sides of the double-sided pressure-sensitive adhesive sheet may be protected by two release liners, respectively, or one release liner having release surfaces on both sides is wound into a roll. It may be protected in a form (wound body). A release liner is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when applied to an adherend. Note that the release liner may not necessarily be provided.
　上記はく離ライナーとしては、慣用の剥離紙などを使用でき、特に限定されないが、例えば、剥離処理層を有する基材、フッ素ポリマーからなる低接着性基材や無極性ポリマーからなる低接着性基材などが挙げられる。上記剥離処理層を有する基材としては、例えば、シリコーン系、長鎖アルキル系、フッ素系、硫化モリブデン等の剥離処理剤により表面処理されたプラスチックフィルムや紙などが挙げられる。上記フッ素ポリマーからなる低接着性基材におけるフッ素系ポリマーとしては、例えば、ポリテトラフルオロエチレン、ポリクロロトリフルオロエチレン、ポリフッ化ビニル、ポリフッ化ビニリデン、テトラフルオロエチレン－ヘキサフルオロプロピレン共重合体、クロロフルオロエチレン－フッ化ビニリデン共重合体などが挙げられる。また、上記無極性ポリマーとしては、例えば、オレフィン系樹脂（例えば、ポリエチレン、ポリプロピレン等）などが挙げられる。なお、はく離ライナーは公知乃至慣用の方法により形成することができる。また、はく離ライナーの厚さも特に限定されない。 As the release liner, a conventional release paper or the like can be used, and is not particularly limited. etc. Examples of the base material having the release treatment layer include plastic films and paper surface-treated with release agents such as silicone, long-chain alkyl, fluorine, and molybdenum sulfide. Examples of the fluorine-based polymer in the low-adhesive substrate made of the fluorine polymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chloro fluoroethylene-vinylidene fluoride copolymer and the like. Examples of the non-polar polymer include olefin resins (eg, polyethylene, polypropylene, etc.). The release liner can be formed by a known or commonly used method. Also, the thickness of the release liner is not particularly limited.
　上記両面粘着シートは、電気電子機器に備えられる部材に貼り合わせて使用される、電気電子部材貼付用であることが好ましい。上記両面粘着シートは、特に、両面粘着シートの両方の粘着面にそれぞれ、電気電子機器に備えられる部品を貼り合わせて使用される用途、すなわち電気電子機器における部材同士の固定用であることが好ましい。上記両面粘着シートは、上記部材同士を固定する用途、あるいは仮固定する用途のいずれに使用されるものであってもよい。例えば、両面粘着シートを電気電子機器に備えられる部品の固定や仮固定に用いる場合、両面粘着シートの貼り付け作業に不具合が起こったために両面粘着シートを剥離してリワークしなければならない場合があったり、両面粘着シートを貼り付けた被着体を備えた部材を修理、交換、検査、リサイクル等するために両面粘着シートを剥離しなければならない場合があったりする。このように、両面粘着シートを、例えば、電気電子機器に備えられる部品の固定や仮固定に用いる場合には、特に、両面粘着シートを除去する頻度が高い。 The double-sided pressure-sensitive adhesive sheet is preferably for attaching to electrical and electronic members, which is used by being attached to members provided in electrical and electronic equipment. The above-mentioned double-sided pressure-sensitive adhesive sheet is particularly preferably used for bonding parts provided in electrical and electronic equipment to both adhesive surfaces of the double-sided pressure-sensitive adhesive sheet, i.e., for fixing members to each other in electrical and electronic equipment. . The double-sided pressure-sensitive adhesive sheet may be used for fixing the members together or temporarily fixing them. For example, when a double-sided adhesive sheet is used for fixing or temporarily fixing parts provided in electrical and electronic equipment, there are cases in which it is necessary to peel off the double-sided adhesive sheet and rework due to a problem in attaching the double-sided adhesive sheet. Also, there are cases where the double-sided pressure-sensitive adhesive sheet must be peeled off in order to repair, replace, inspect, recycle, or the like a member having an adherend to which the double-sided pressure-sensitive adhesive sheet is attached. Thus, when the double-sided pressure-sensitive adhesive sheet is used, for example, for fixing or temporarily fixing components provided in an electric/electronic device, the frequency of removing the double-sided pressure-sensitive adhesive sheet is particularly high.
　上記両面粘着シートは、中でも、光学部材（特に、電気電子機器）の外枠同士を貼り合わせて使用されることが好ましい。このため、上記両面粘着シートは、５ｍｍ以下、好ましくは３ｍｍ以下の幅であっても好ましく使用することができる。 The above-mentioned double-sided pressure-sensitive adhesive sheet is preferably used by pasting the outer frames of optical members (especially electrical and electronic devices) together. Therefore, the double-sided pressure-sensitive adhesive sheet can be preferably used even if it has a width of 5 mm or less, preferably 3 mm or less.
　なお、「電気電子機器」とは、電気機器または電子機器の少なくともいずれかに該当する機器をいう。上記電気電子機器としては、例えば、液晶ディスプレイ、エレクトロルミネッセンスディスプレイ、プラズマディスプレイ等の画像表示装置や、携帯電子機器などが挙げられる。 "Electrical and electronic equipment" refers to equipment that corresponds to at least either electrical equipment or electronic equipment. Examples of the electric/electronic devices include image display devices such as liquid crystal displays, electroluminescence displays, and plasma displays, and mobile electronic devices.
　上記携帯電子機器としては、例えば、携帯電話、スマートフォン、タブレット型パソコン、ノート型パソコン、各種ウェアラブル機器（例えば、腕時計のように手首に装着するリストウェア型、クリップやストラップ等で体の一部に装着するモジュラー型、メガネ型（単眼型や両眼型。ヘッドマウント型も含む。）を包含するアイウェア型、シャツや靴下、帽子等に例えばアクセサリの形態で取り付ける衣服型、イヤホンのように耳に取り付けるイヤウェア型等）、デジタルカメラ、デジタルビデオカメラ、音響機器（携帯音楽プレーヤー、ＩＣレコーダー等）、計算機（電卓等）、携帯ゲーム機器、電子辞書、電子手帳、電子書籍、車載用情報機器、携帯ラジオ、携帯テレビ、携帯プリンター、携帯スキャナ、携帯モデムなどが挙げられる。なお、本明細書において「携帯」とは、単に携帯することが可能であるだけでは充分ではなく、個人（標準的な成人）が相対的に容易に持ち運び可能なレベルの携帯性を有することを意味するものとする。上記両面粘着シートは、例えば、粘着剤層が上記携帯電子機器の部材に密着するように用いられる。 Examples of the portable electronic devices include mobile phones, smartphones, tablet computers, notebook computers, and various wearable devices (for example, wrist wear types that are worn on the wrist like wristwatches, clips, straps, etc. that are attached to a part of the body) Modular type to be worn, eyewear type including eyeglass type (monocular type and binocular type, including head-mounted type), clothing type that can be attached to shirts, socks, hats, etc. in the form of accessories, ears such as earphones earwear type, etc.), digital cameras, digital video cameras, audio equipment (portable music players, IC recorders, etc.), calculators (calculators, etc.), portable game devices, electronic dictionaries, electronic notebooks, electronic books, in-vehicle information equipment, Examples include portable radios, portable televisions, portable printers, portable scanners, and portable modems. In this specification, the term “portable” means not only being able to be carried but also having a level of portability that allows individuals (standard adults) to relatively easily carry it. shall mean. The double-sided pressure-sensitive adhesive sheet is used, for example, so that the pressure-sensitive adhesive layer adheres to the member of the portable electronic device.
　以下に実施例を挙げて本発明をより詳細に説明するが、本発明はこれらの実施例により何ら限定されるものではない。 Although the present invention will be described in more detail below with reference to examples, the present invention is not limited by these examples.
　製造例１：シロップ（１）の合成
　モノマー成分として、ブチルアクリレート（ＢＡ）：７０質量部、アクリル酸（ＡＡ）：７質量部、およびイソボルニルアクリレート（ＩＢＸＡ、Ｔｇ：９７℃）：２３質量部が混合された液状のモノマー混合物（モノマー組成物）に、光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．０５質量部を配合した後、粘度（ＢＨ粘度計Ｎｏ．５ローター、１０ｒｐｍ、測定温度：３０℃）が約１５Ｐａ・ｓになるまで紫外線をパルス照射して、モノマー成分の一部が重合した部分重合体（重合率：約８％）を含むシロップ（部分重合物）を得た。 Production Example 1: Synthesis of Syrup (1) As monomer components, butyl acrylate (BA): 70 parts by mass, acrylic acid (AA): 7 parts by mass, and isobornyl acrylate (IBXA, Tg: 97°C): 23 parts by mass 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651”, IGM Resins B.V.) as a photopolymerization initiator is added to a liquid monomer mixture (monomer composition) in which parts are mixed. .): After blending 0.05 parts by mass, the viscosity (BH viscometer No. 5 rotor, 10 rpm, measurement temperature: 30 ° C.) is pulse-irradiated with ultraviolet rays until it reaches about 15 Pa s, and the monomer component is A syrup (partial polymer) containing a partially polymerized partial polymer (polymerization rate: about 8%) was obtained.
　製造例２：シロップ（２）の合成
　モノマー成分として、ブチルアクリレート（ＢＡ）：７０質量部、アクリル酸（ＡＡ）：７質量部、およびジシクロペンタニルアクリレート（ＤＣＰＡ、Ｔｇ：約１００℃）：２３質量部が混合された液状のモノマー混合物（モノマー組成物）に、光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．０５質量部を配合した後、粘度（ＢＨ粘度計Ｎｏ．５ローター、１０ｒｐｍ、測定温度：３０℃）が約１５Ｐａ・ｓになるまで紫外線をパルス照射して、モノマー成分の一部が重合した部分重合体（重合率：約８％）を含むシロップ（部分重合物）を得た。 Production Example 2: Synthesis of Syrup (2) As monomer components, butyl acrylate (BA): 70 parts by mass, acrylic acid (AA): 7 parts by mass, and dicyclopentanyl acrylate (DCPA, Tg: about 100°C): 23 parts by mass of a mixed liquid monomer mixture (monomer composition) was added with 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651”, IGM Resins B V.): After blending 0.05 parts by mass, the viscosity (BH viscometer No. 5 rotor, 10 rpm, measurement temperature: 30 ° C.) is pulse-irradiated with ultraviolet rays until the viscosity reaches about 15 Pa s, and the monomer A syrup (partially polymerized product) containing a partially polymerized component (polymerization rate: about 8%) was obtained.
　製造例３：シロップ（３）の合成
　モノマー成分として、ブチルアクリレート（ＢＡ）：７８質量部、アクリル酸（ＡＡ）：７質量部、およびアクリロイルモルホリン（ＡＣＭＯ、Ｔｇ：約１４５℃）：１５質量部が混合された液状のモノマー混合物（モノマー組成物）に、光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．０５質量部を配合した後、粘度（ＢＨ粘度計Ｎｏ．５ローター、１０ｒｐｍ、測定温度：３０℃）が約１５Ｐａ・ｓになるまで紫外線をパルス照射して、モノマー成分の一部が重合した部分重合体（重合率：約８％）を含むシロップ（部分重合物）を得た。 Production Example 3: Synthesis of syrup (3) As monomer components, butyl acrylate (BA): 78 parts by mass, acrylic acid (AA): 7 parts by mass, and acryloylmorpholine (ACMO, Tg: about 145 ° C.): 15 parts by mass 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651”, IGM Resins B.V.) as a photopolymerization initiator in a liquid monomer mixture (monomer composition) mixed with (Manufacturer): After blending 0.05 parts by mass, pulse irradiation with ultraviolet light is performed until the viscosity (BH viscometer No. 5 rotor, 10 rpm, measurement temperature: 30 ° C.) reaches about 15 Pa s, and one of the monomer components A syrup (partially polymerized product) containing a partially polymerized partial polymer (polymerization rate: about 8%) was obtained.
　製造例４：シロップ（４）の合成
　モノマー成分として、ブチルアクリレート（ＢＡ）：７０質量部、アクリル酸（ＡＡ）：７質量部、およびシクロヘキシルアクリレート（ＣＨＡ、Ｔｇ：１５℃）：２３質量部が混合された液状のモノマー混合物（モノマー組成物）に、光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．０５質量部を配合した後、粘度（ＢＨ粘度計Ｎｏ．５ローター、１０ｒｐｍ、測定温度：３０℃）が約１５Ｐａ・ｓになるまで紫外線をパルス照射して、モノマー成分の一部が重合した部分重合体（重合率：約８％）を含むシロップ（部分重合物）を得た。 Production Example 4: Synthesis of syrup (4) As monomer components, butyl acrylate (BA): 70 parts by mass, acrylic acid (AA): 7 parts by mass, and cyclohexyl acrylate (CHA, Tg: 15 ° C.): 23 parts by mass To the mixed liquid monomer mixture (monomer composition), 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651” manufactured by IGM Resins B.V.) as a photopolymerization initiator was added. ): After blending 0.05 parts by mass, the viscosity (BH viscometer No. 5 rotor, 10 rpm, measurement temperature: 30 ° C.) is pulse-irradiated with ultraviolet rays until it reaches about 15 Pa s, and a part of the monomer component A syrup (partial polymer) containing a partial polymer (polymerization rate: about 8%) was obtained.
　実施例１
　製造例１で得られたシロップ（１）：１００質量部、シクロヘキシルアクリレート（ＣＨＡ）：１３質量部、アクリル酸（ＡＡ）：２質量部、カーボンブラックを含む黒色顔料（商品名「マルチラックＡ９０３」、トーヨーカラー株式会社製）：０．２質量部、フィラーとしてのポリエチレン粉末（商品名「フローセンＵＦ－８０」、住友精化株式会社製）：２質量部、１，６－ヘキサンジオールジアクリレート（ＨＤＤＡ）：０．１２質量部、および光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．１質量部を配合した後、ディスパーを用いて均一に混合し、その後、脱泡して、アクリル系粘着剤組成物を得た。 Example 1
Syrup (1) obtained in Production Example 1: 100 parts by mass, cyclohexyl acrylate (CHA): 13 parts by mass, acrylic acid (AA): 2 parts by mass, black pigment containing carbon black (trade name "Multilac A903" , Toyocolor Co., Ltd.): 0.2 parts by mass, polyethylene powder as a filler (trade name "Flosen UF-80", manufactured by Sumitomo Seika Co., Ltd.): 2 parts by mass, 1,6-hexanediol diacrylate ( HDDA): 0.12 parts by mass, and 2,2-dimethoxy-1,2-diphenylethan-1-one as a photopolymerization initiator (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.): 0.12 parts by mass. After blending 1 part by mass, they were uniformly mixed using a disper, and then defoamed to obtain an acrylic pressure-sensitive adhesive composition.
　得られたアクリル系粘着剤組成物を、片面をシリコーンで剥離処理した厚さ３８μｍのポリエチレンテレフタレートフィルム（製品名「ＭＲＦ＃３８」、三菱ケミカル株式会社製）上に、粘着剤層厚さが２００μｍとなるようにアプリケーターを用いて塗布し、塗布層を形成した。 The resulting acrylic pressure-sensitive adhesive composition was coated on a 38-μm-thick polyethylene terephthalate film (product name “MRF#38”, manufactured by Mitsubishi Chemical Corporation) whose one side was treated with silicone for release, and the pressure-sensitive adhesive layer thickness was 200 μm. was applied using an applicator to form a coating layer.
　次いで、片面をシリコーンで剥離処理した厚さ２５μｍのポリエチレンテレフタレートフィルム（製品名「ＭＲＥ＃２５」、三菱ケミカル株式会社製）の剥離処理面が上記塗布層側になるように塗布層を被覆して、酸素を遮断した。その後、このフィルムの上面からブラックライトランプにて、照度４ｍＷ／ｃｍ2（ＵＶチェッカー「ＵＶＲ－Ｔ１」、株式会社トプコン製、測定時の最大感度は約３５０ｎｍ）の紫外線を１８０秒間照射して、厚さ２００μｍの粘着剤層を形成し、両面粘着シートを作製した。 Next, a 25 μm-thick polyethylene terephthalate film (product name “MRE #25”, manufactured by Mitsubishi Chemical Corporation) whose one side was release-treated with silicone was coated with the coating layer so that the release-treated surface was on the side of the coating layer. , oxygen was cut off. After that, from the upper surface of this film, a black light lamp was used to irradiate ultraviolet rays with an illuminance of 4 mW/cm 2 (UV checker "UVR-T1", manufactured by Topcon Corporation, maximum sensitivity at measurement: about 350 nm) for 180 seconds. A pressure-sensitive adhesive layer having a thickness of 200 μm was formed to prepare a double-sided pressure-sensitive adhesive sheet.
　実施例２
　製造例１で得られたシロップ（１）に代えて製造例２で得られたシロップ（２）を用いたこと以外は実施例１と同様にして実施例２の両面粘着シートを作製した。 Example 2
A double-sided pressure-sensitive adhesive sheet of Example 2 was produced in the same manner as in Example 1, except that the syrup (2) obtained in Production Example 2 was used in place of the syrup (1) obtained in Production Example 1.
　実施例３
　製造例２で得られたシロップ（２）：１００質量部、アクリル酸（ＡＡ）：２質量部、カーボンブラックを含む黒色顔料（商品名「マルチラックＡ９０３」、トーヨーカラー株式会社製）：０．２質量部、フィラーとしてのポリエチレン粉末（商品名「フローセンＵＦ－８０」、住友精化株式会社製）：２質量部、１，６－ヘキサンジオールジアクリレート（ＨＤＤＡ）：０．１２質量部、および光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．１質量部を配合した後、ディスパーを用いて均一に混合し、その後、脱泡して、アクリル系粘着剤組成物を得た。 Example 3
Syrup (2) obtained in Production Example 2: 100 parts by mass, acrylic acid (AA): 2 parts by mass, black pigment containing carbon black (trade name "Multilac A903", manufactured by Toyocolor Co., Ltd.): 0. 2 parts by mass, polyethylene powder as a filler (trade name “Flosen UF-80”, manufactured by Sumitomo Seika Co., Ltd.): 2 parts by mass, 1,6-hexanediol diacrylate (HDDA): 0.12 parts by mass, and 2,2-dimethoxy-1,2-diphenylethan-1-one as a photopolymerization initiator (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.): After blending 0.1 part by mass, disper was applied. It was mixed uniformly using the above, and then defoamed to obtain an acrylic pressure-sensitive adhesive composition.
　上記で得られたアクリル系粘着剤組成物を用いたこと以外は実施例１と同様にして実施例３の両面粘着シートを作製した。 A double-sided pressure-sensitive adhesive sheet of Example 3 was produced in the same manner as in Example 1, except that the acrylic pressure-sensitive adhesive composition obtained above was used.
　実施例４
　製造例２で得られたシロップ（２）：１００質量部、シクロヘキシルアクリレート（ＣＨＡ）：２０質量部、カーボンブラックを含む黒色顔料（商品名「マルチラックＡ９０３」、トーヨーカラー株式会社製）：０．２質量部、フィラーとしてのポリエチレン粉末（商品名「フローセンＵＦ－８０」、住友精化株式会社製）：２質量部、１，６－ヘキサンジオールジアクリレート（ＨＤＤＡ）：０．１２質量部、および光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．１質量部を配合した後、ディスパーを用いて均一に混合し、その後、脱泡して、アクリル系粘着剤組成物を得た。 Example 4
Syrup (2) obtained in Production Example 2: 100 parts by mass, cyclohexyl acrylate (CHA): 20 parts by mass, black pigment containing carbon black (trade name "Multilac A903", manufactured by Toyocolor Co., Ltd.): 0. 2 parts by mass, polyethylene powder as a filler (trade name “Flosen UF-80”, manufactured by Sumitomo Seika Co., Ltd.): 2 parts by mass, 1,6-hexanediol diacrylate (HDDA): 0.12 parts by mass, and 2,2-dimethoxy-1,2-diphenylethan-1-one as a photopolymerization initiator (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.): After blending 0.1 part by mass, disper was applied. It was mixed uniformly using the above, and then defoamed to obtain an acrylic pressure-sensitive adhesive composition.
　上記で得られたアクリル系粘着剤組成物を用いたこと以外は実施例１と同様にして実施例４の両面粘着シートを作製した。 A double-sided pressure-sensitive adhesive sheet of Example 4 was produced in the same manner as in Example 1, except that the acrylic pressure-sensitive adhesive composition obtained above was used.
　実施例５
　製造例１で得られたシロップ（１）に代えて製造例３で得られたシロップ（３）を用いたこと以外は実施例１と同様にして実施例５の両面粘着シートを作製した。 Example 5
A double-sided pressure-sensitive adhesive sheet of Example 5 was produced in the same manner as in Example 1 except that the syrup (3) obtained in Production Example 3 was used in place of the syrup (1) obtained in Production Example 1.
　実施例６
　フィラーとしてシリコーンゴム粒子（商品名「トレフィル　Ｅ－６０６」、東レ株式会社製）：２質量部を用いたこと以外は実施例１と同様にして実施例６の両面粘着シートを作製した。 Example 6
A double-sided pressure-sensitive adhesive sheet of Example 6 was prepared in the same manner as in Example 1, except that 2 parts by mass of silicone rubber particles (trade name “Torayfil E-606” manufactured by Toray Industries, Inc.) were used as a filler.
　実施例７
　フィラーとしてポリエチレン粒子（商品名「フロービーズ　ＦＢＲＰ」、住友精化株式会社製）：２質量部を用いたこと以外は実施例１と同様にして実施例７の両面粘着シートを作製した。 Example 7
A double-sided pressure-sensitive adhesive sheet of Example 7 was prepared in the same manner as in Example 1, except that 2 parts by mass of polyethylene particles (trade name “Flobeads FBRP”, manufactured by Sumitomo Seika Chemicals Co., Ltd.) were used as a filler.
　比較例１
　製造例２で得られたシロップ（２）：１００質量部、カーボンブラックを含む黒色顔料（商品名「マルチラックＡ９０３」、トーヨーカラー株式会社製）：０．２質量部、フィラーとしてのポリエチレン粉末（商品名「フローセンＵＦ－８０」、住友精化株式会社製）：２質量部、１，６－ヘキサンジオールジアクリレート（ＨＤＤＡ）：０．１２質量部、および光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）：０．１質量部を配合した後、ディスパーを用いて均一に混合し、その後、脱泡して、アクリル系粘着剤組成物を得た。 Comparative example 1
Syrup (2) obtained in Production Example 2: 100 parts by mass, black pigment containing carbon black (trade name "Multilac A903", manufactured by Toyocolor Co., Ltd.): 0.2 parts by mass, polyethylene powder as a filler ( Trade name “Flosen UF-80” manufactured by Sumitomo Seika Co., Ltd.): 2 parts by mass, 1,6-hexanediol diacrylate (HDDA): 0.12 parts by mass, and 2,2- as a photopolymerization initiator Dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.): After blending 0.1 parts by mass, uniformly mixing using a disper, and then removing After foaming, an acrylic pressure-sensitive adhesive composition was obtained.
　上記で得られたアクリル系粘着剤組成物を用いたこと以外は実施例１と同様にして比較例１の両面粘着シートを作製した。 A double-sided pressure-sensitive adhesive sheet of Comparative Example 1 was produced in the same manner as in Example 1, except that the acrylic pressure-sensitive adhesive composition obtained above was used.
　比較例２
　光重合開始剤としての２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名「ＯＭＮＩＲＡＤ６５１」、ＩＧＭ　Ｒｅｓｉｎｓ　Ｂ．Ｖ．製）の配合量を０．０５質量部としたこと以外は比較例１と同様にして比較例２の両面粘着シートを作製した。 Comparative example 2
Except that the amount of 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name “OMNIRAD651”, manufactured by IGM Resins B.V.) as a photopolymerization initiator was set to 0.05 parts by mass. A double-sided pressure-sensitive adhesive sheet of Comparative Example 2 was prepared in the same manner as in Comparative Example 1.
　比較例３
　製造例２で得られたシロップ（２）に代えて製造例４で得られたシロップ（４）を用いたこと以外は比較例１と同様にして比較例３の両面粘着シートを作製した。 Comparative example 3
A double-sided pressure-sensitive adhesive sheet of Comparative Example 3 was prepared in the same manner as in Comparative Example 1, except that the syrup (4) obtained in Production Example 4 was used in place of the syrup (2) obtained in Production Example 2.
＜評価＞
　実施例および比較例で得られた両面粘着シートについて、以下の評価を行った。結果を表に示す。なお、表における各成分の配合量は質量部を示す。 <Evaluation>
The double-sided pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in the table. In addition, the compounding quantity of each component in a table|surface shows a mass part.
（１）動的粘弾性測定
　実施例および比較例で作製した両面粘着シートを複数枚重ね合わせることにより、厚さ約２ｍｍの粘着剤層を作製した。この粘着剤層を直径７．９ｍｍの円盤状に打ち抜いた試料をパラレルプレートで挟み込んで固定し、２３℃、５０％ＲＨの環境下、粘弾性試験機（商品名「ＡＲＥＳレオメーター」、ティー・エー・インスツルメント社製）を用いて以下の条件で動的粘弾性測定を行い、貯蔵弾性率Ｇ’（－２０℃）、貯蔵弾性率Ｇ’（２３℃）、貯蔵弾性率Ｇ’（６５℃）、ガラス転移温度、およびｔａｎδのピークトップ値を算出した。
　測定モード：せん断モード
　温度範囲　：－７０℃～１５０℃
　昇温速度　：５℃／ｍｉｎ
　測定周波数：１Ｈｚ (1) Measurement of dynamic viscoelasticity A pressure-sensitive adhesive layer having a thickness of about 2 mm was prepared by stacking a plurality of double-sided pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples. A disk-shaped sample with a diameter of 7.9 mm was punched out of this adhesive layer and fixed by sandwiching it between parallel plates. A Instruments Co., Ltd.) was used to perform dynamic viscoelasticity measurement under the following conditions, and storage elastic modulus G' (-20 ° C.), storage elastic modulus G' (23 ° C.), storage elastic modulus G' ( 65° C.), the glass transition temperature, and the peak top value of tan δ were calculated.
Measurement mode: Shear mode Temperature range: -70°C to 150°C
Heating rate: 5°C/min
Measurement frequency: 1Hz
（２）せん断接着力
　実施例および比較例で作製した両面粘着シートを２０ｍｍ×２０ｍｍのサイズにカットして測定サンプルを作製した。２３℃、５０％ＲＨの環境下にて、上記測定サンプルの各粘着面を２枚のステンレス鋼板の表面にそれぞれ重ねて２ｋｇのローラを１往復させて圧着した。これを同環境下に３０分間放置した後、引張試験機を用いて、引張速度１０ｍｍ／分、剥離角度０°の条件で、せん断接着力を測定した。具体的には図２に示すように、測定サンプル１０の一方の粘着面１０ａをステンレス鋼板２１に貼り合わせ、測定サンプル１０の他方の粘着面１０ｂをステンレス鋼板２２に貼り合わせて圧着した。これを上述の速度で図２中の矢印方向（すなわち、せん断方向）に引っ張り、２０ｍｍ×２０ｍｍ当たりの剥離強度を測定する。得られた値からせん断接着力［ＭＰａ］を求めた。引張試験機としては、万能引張圧縮試験機（製品名「ＴＧ－１ｋＮ」、ミネベア社製）を使用した。 (2) Shear Adhesive Strength A measurement sample was prepared by cutting the double-sided pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples into a size of 20 mm×20 mm. In an environment of 23° C. and 50% RH, each adhesive surface of the measurement sample was superimposed on the surface of two stainless steel plates and pressed by reciprocating a 2 kg roller once. After leaving this in the same environment for 30 minutes, the shear adhesive strength was measured using a tensile tester under the conditions of a tensile speed of 10 mm/min and a peeling angle of 0°. Specifically, as shown in FIG. 2, one adhesive surface 10a of the measurement sample 10 was adhered to a stainless steel plate 21, and the other adhesive surface 10b of the measurement sample 10 was adhered to a stainless steel plate 22 and pressure-bonded. This is pulled in the direction of the arrow in FIG. 2 (that is, shear direction) at the above speed, and the peel strength per 20 mm×20 mm is measured. A shear adhesive strength [MPa] was obtained from the obtained value. As a tensile tester, a universal tension/compression tester (product name “TG-1kN”, manufactured by Minebea Co., Ltd.) was used.
（３）耐衝撃性
　実施例および比較例で作製した、はく離ライナーに挟まれた状態の両面粘着シートを、外径２４．５ｍｍ角、幅２ｍｍの枠状に打ち抜いた。その後、両面粘着シートからはく離ライナーを剥離し、厚さ２ｍｍ、外形５０ｍｍ角の正方形の中央部に穴の開いたステンレスプレートと、厚さ３ｍｍ、外形２５ｍｍ角の正方形のステンレスプレートとの間に挟み込んで圧着し、温度５０℃の環境下に２時間静置し、その後常温に戻して評価サンプルとした。デュポン式衝撃試験機（株式会社東洋精機製作所製）の台座の上に、長さ５０ｍｍ、外径４９ｍｍ、内径４３ｍｍの円柱状の測定台を設置し、その上に試験片を、正方形のステンレスプレート（穴の開いていないステンレスプレート）を下側にして載せた。先端半径３．１ｍｍのステンレス製の撃芯を試験片に載せ、落下おもり重量と落下高さを、１００ｇにて５０～５００ｍｍまで５０ｍｍずつ変化、１５０ｇにて３５０～５００ｍｍまで５０ｍｍずつ変化、２００ｇにて４００～５００ｍｍまで５０ｍｍずつ変化、３００ｇにて３５０～５００ｍｍまで５０ｍｍずつ変化させ、剥がれが生じるまでエネルギーが増えていくようにした。この際に、評価済みであるエネルギーについては、試験を行わず、エネルギー量が重複しないように荷重と高さを設定した。その後、少なくともいずれか一方のステンレスプレートが剥がれる前までのエネルギーを荷重×高さで算出して結果とした。 (3) Impact resistance The double-faced pressure-sensitive adhesive sheets sandwiched between release liners produced in Examples and Comparative Examples were punched into a frame shape with an outer diameter of 24.5 mm square and a width of 2 mm. After that, the release liner was peeled off from the double-sided adhesive sheet and sandwiched between a square stainless steel plate with a thickness of 2 mm and an outer diameter of 50 mm square with a hole in the center and a square stainless steel plate with an outer diameter of 3 mm and an outer diameter of 25 mm square. and left for 2 hours in an environment at a temperature of 50° C., and then returned to room temperature to obtain an evaluation sample. A cylindrical measurement table with a length of 50 mm, an outer diameter of 49 mm, and an inner diameter of 43 mm is installed on the pedestal of a DuPont impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and a test piece is placed on it, a square stainless steel plate. (stainless steel plate without holes) was placed on the bottom side. A stainless steel striking core with a tip radius of 3.1 mm is placed on the test piece, and the weight and height of the falling weight are changed by 50 mm from 50 to 500 mm at 100 g, by 50 mm from 350 to 500 mm at 150 g, and then to 200 g. At 300 g, the energy was changed by 50 mm from 400 to 500 mm, and at 300 g by 50 mm from 350 to 500 mm, the energy was increased until peeling occurred. At this time, no test was performed on the energy that had already been evaluated, and the load and height were set so that the amount of energy would not overlap. After that, the energy until at least one of the stainless steel plates peeled off was calculated by multiplying the load by the height, and the result was obtained.
（４）１８０°剥離強度
　実施例および比較例で作製した両面粘着シートについて、２３℃、５０％ＲＨの測定環境下において、一方の粘着面からはく離ライナーを剥離して厚さ５０μｍのＰＥＴフィルムを貼り付けて裏打ちし、幅２５ｍｍ、長さ１００ｍｍのサイズにカットして測定サンプルを作製した。作製した測定サンプルにつき、２３℃、５０％ＲＨの環境下にて、上記測定サンプルの他方の粘着面からはく離ライナーを剥離して、当該粘着面をステンレス鋼板（ＳＵＳ３０４ＢＡ板）の表面に２ｋｇのローラを１往復させて圧着した。これを同環境下に３０分間放置した後、万能引張圧縮試験機を使用して、ＪＩＳ　Ｚ０２３７（２０００）に準じて、引張速度３００ｍｍ／分、剥離角度１８０°の条件で、剥離強度を測定した。万能引張圧縮試験機として、商品名「引張圧縮試験機、ＴＧ－１ｋＮ」（ミネベア社製）を使用した。 (4) 180° peel strength For the double-sided PSA sheets prepared in Examples and Comparative Examples, the release liner was peeled off from one adhesive surface under a measurement environment of 23°C and 50% RH to form a PET film having a thickness of 50 µm. A measurement sample was prepared by pasting and lining, and cutting into a size of 25 mm in width and 100 mm in length. For the prepared measurement sample, in an environment of 23° C. and 50% RH, the release liner was peeled off from the other adhesive surface of the measurement sample, and the adhesive surface was placed on the surface of a stainless steel plate (SUS304BA plate) with a 2 kg roller. was crimped by reciprocating once. After leaving it under the same environment for 30 minutes, the peel strength was measured using a universal tension/compression tester according to JIS Z0237 (2000) under the conditions of a tensile speed of 300 mm/min and a peel angle of 180°. . As a universal tension/compression tester, a trade name "Tension/Compression Tester, TG-1kN" (manufactured by Minebea Co., Ltd.) was used.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示すように、本発明の両面粘着シートは、耐衝撃性に優れ、高いせん断接着力を有し、且つ初期粘着性に優れていることが確認された。一方、粘着剤層のＴｇが低く、また１８０°剥離強度が小さい場合（比較例）、初期粘着性に劣ると判断された。 As shown in Table 1, it was confirmed that the double-sided pressure-sensitive adhesive sheet of the present invention has excellent impact resistance, high shear adhesive strength, and excellent initial adhesiveness. On the other hand, when the Tg of the pressure-sensitive adhesive layer was low and the 180° peel strength was low (Comparative Example), it was judged that the initial pressure-sensitive adhesiveness was poor.
１　両面粘着シート
２　粘着剤層
３，４　はく離ライナー
１０　測定サンプル
１０ａ，１０ｂ　粘着面
２１，２２　ステンレス鋼板 1 double-sided adhesive sheet 2 adhesive layers 3, 4 release liner 10 measurement samples 10a, 10b adhesive surfaces 21, 22 stainless steel plate

Claims (7)

  1. 　粘着剤層からなる両面粘着シートであり、
    　前記粘着剤層は、ペースポリマーとしてアクリル系ポリマーを含む活性エネルギー線硬化型のアクリル系粘着剤層であり、
    　前記アクリル系ポリマーは、炭素数２～７の直鎖または分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステル（Ａ）に由来する構成単位を５０質量％以上含み、
    　前記粘着剤層は、ガラス転移温度が０℃以上であり、－２０℃における貯蔵弾性率Ｇ’が１０ＭＰａ以上、６５℃における貯蔵弾性率Ｇ’が０．０５ＭＰａ以上であり、
    　前記両面粘着シートの一方の粘着面に厚さ５０μｍのポリエチレンテレフタレートフィルムを貼り付けた状態での２３℃で測定されるステンレス鋼板に対する１８０°剥離強度は２０Ｎ／２０ｍｍ以上である、両面粘着シート。     A double-sided adhesive sheet comprising an adhesive layer,
    The pressure-sensitive adhesive layer is an active energy ray-curable acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer,
    The acrylic polymer contains 50% by mass or more of structural units derived from a (meth)acrylic acid alkyl ester (A) having a linear or branched alkyl group having 2 to 7 carbon atoms,
    The pressure-sensitive adhesive layer has a glass transition temperature of 0° C. or higher, a storage elastic modulus G′ at −20° C. of 10 MPa or higher, and a storage elastic modulus G′ at 65° C. of 0.05 MPa or higher.
    A double-sided pressure-sensitive adhesive sheet having a 180° peel strength against a stainless steel plate measured at 23°C of 20 N/20 mm or more when a polyethylene terephthalate film having a thickness of 50 µm is adhered to one pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet.
  2. 　前記（メタ）アクリル酸アルキルエステル（Ａ）は（メタ）アクリル酸ブチルを含み、前記アクリル系ポリマー中の（メタ）アクリル酸ブチルに由来する構成単位の割合は５０質量％以上である、請求項１に記載の両面粘着シート。 The (meth)acrylic acid alkyl ester (A) contains butyl (meth)acrylate, and the ratio of structural units derived from butyl (meth)acrylate in the acrylic polymer is 50% by mass or more. 2. The double-sided pressure-sensitive adhesive sheet according to 1.
  3. 　前記アクリル系ポリマーは、ポリマーを構成するモノマー成分として多官能性モノマーを含む、請求項１または２に記載の両面粘着シート。 The double-sided pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the acrylic polymer contains a polyfunctional monomer as a monomer component constituting the polymer.
  4. 　前記アクリル系ポリマーは光重合開始剤に由来する構造部を有する、請求項１～３のいずれか１項に記載の両面粘着シート。 The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the acrylic polymer has a structure derived from a photopolymerization initiator.
  5. 　前記アクリル系ポリマーは、ホモポリマーのガラス転移温度が０℃以上であり且つ非芳香族性環を有するモノマー成分（Ｂ）に由来する構成単位を含む、請求項１～３のいずれか１項に記載の両面粘着シート。 4. The acrylic polymer according to any one of claims 1 to 3, wherein the glass transition temperature of the homopolymer is 0 ° C. or higher and contains a structural unit derived from a monomer component (B) having a non-aromatic ring. Double-sided adhesive sheet described.
  6. 　電気電子機器における部材同士の固定用である請求項１～５のいずれか１項に記載の両面粘着シート。 The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 5, which is for fixing members to each other in electrical and electronic equipment.
  7. 　請求項６に記載の両面粘着シートを備え、
    　前記両面粘着シートは両方の粘着面で部材同士を固定している、電気電子機器。     Equipped with the double-sided pressure-sensitive adhesive sheet according to claim 6,
    The electric/electronic device, wherein the double-sided pressure-sensitive adhesive sheet fixes the members to each other with both pressure-sensitive adhesive surfaces.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014047254A (en) * 2012-08-30 2014-03-17 Nitto Denko Corp Double-sided adhesive sheet, laminate and removal method of plate
KR20160135023A (en) * 2015-05-14 2016-11-24 삼성전자주식회사 Adhesive film and flexibile display apparatus comprising the same
US20170166786A1 (en) * 2015-12-11 2017-06-15 Samsung Sdi Co., Ltd. Adhesive sheet and optical display comprising the same
KR20170097856A (en) * 2016-02-19 2017-08-29 주식회사 엘지화학 Pressure Sensitive Adhesive composition using foldable display
WO2017159789A1 (en) * 2016-03-17 2017-09-21 王子ホールディングス株式会社 Adhesive sheet and laminate body
KR20170120853A (en) * 2016-04-22 2017-11-01 삼성에스디아이 주식회사 Adhesive film, optical member comprising the same and optical display apparatus comprising the same
JP2019510851A (en) * 2016-03-24 2019-04-18 ダウ シリコーンズ コーポレーション Optical silicone double-sided tape comprising a silicone base layer having low storage modulus
US20190308924A1 (en) * 2016-07-06 2019-10-10 Eastman Chemical Company (meth)acrylic oligomers

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014047254A (en) * 2012-08-30 2014-03-17 Nitto Denko Corp Double-sided adhesive sheet, laminate and removal method of plate
KR20160135023A (en) * 2015-05-14 2016-11-24 삼성전자주식회사 Adhesive film and flexibile display apparatus comprising the same
US20170166786A1 (en) * 2015-12-11 2017-06-15 Samsung Sdi Co., Ltd. Adhesive sheet and optical display comprising the same
KR20170097856A (en) * 2016-02-19 2017-08-29 주식회사 엘지화학 Pressure Sensitive Adhesive composition using foldable display
WO2017159789A1 (en) * 2016-03-17 2017-09-21 王子ホールディングス株式会社 Adhesive sheet and laminate body
JP2019510851A (en) * 2016-03-24 2019-04-18 ダウ シリコーンズ コーポレーション Optical silicone double-sided tape comprising a silicone base layer having low storage modulus
KR20170120853A (en) * 2016-04-22 2017-11-01 삼성에스디아이 주식회사 Adhesive film, optical member comprising the same and optical display apparatus comprising the same
US20190308924A1 (en) * 2016-07-06 2019-10-10 Eastman Chemical Company (meth)acrylic oligomers

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